diff --git a/Cargo.toml b/Cargo.toml
index e37fcad0..8d8a46ae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -86,13 +86,13 @@ ndk-sys = "0.5.0"
 
 [target.'cfg(any(target_os = "ios", target_os = "macos"))'.dependencies]
 core-foundation = "0.9.3"
-objc2 = "0.4.1"
+objc2 = "0.5.0"
 
 [target.'cfg(target_os = "macos")'.dependencies]
 core-graphics = "0.23.1"
 
 [target.'cfg(target_os = "macos")'.dependencies.icrate]
-version = "0.0.4"
+version = "0.1.0"
 features = [
     "dispatch",
     "Foundation",
@@ -108,7 +108,7 @@ features = [
 ]
 
 [target.'cfg(target_os = "ios")'.dependencies.icrate]
-version = "0.0.4"
+version = "0.1.0"
 features = [
     "dispatch",
     "Foundation",
diff --git a/src/platform_impl/ios/monitor.rs b/src/platform_impl/ios/monitor.rs
index 90ed8504..45bace35 100644
--- a/src/platform_impl/ios/monitor.rs
+++ b/src/platform_impl/ios/monitor.rs
@@ -8,6 +8,7 @@ use std::{
 use icrate::Foundation::{MainThreadBound, MainThreadMarker, NSInteger};
 use objc2::mutability::IsRetainable;
 use objc2::rc::Id;
+use objc2::Message;
 
 use super::uikit::{UIScreen, UIScreenMode};
 use crate::{
@@ -20,16 +21,15 @@ use crate::{
 #[derive(Debug)]
 struct MainThreadBoundDelegateImpls<T>(MainThreadBound<Id<T>>);
 
-impl<T: IsRetainable> Clone for MainThreadBoundDelegateImpls<T> {
+impl<T: IsRetainable + Message> Clone for MainThreadBoundDelegateImpls<T> {
     fn clone(&self) -> Self {
-        Self(
-            self.0
-                .get_on_main(|inner, mtm| MainThreadBound::new(Id::clone(inner), mtm)),
-        )
+        Self(MainThreadMarker::run_on_main(|mtm| {
+            MainThreadBound::new(Id::clone(self.0.get(mtm)), mtm)
+        }))
     }
 }
 
-impl<T: IsRetainable> hash::Hash for MainThreadBoundDelegateImpls<T> {
+impl<T: IsRetainable + Message> hash::Hash for MainThreadBoundDelegateImpls<T> {
     fn hash<H: hash::Hasher>(&self, state: &mut H) {
         // SAFETY: Marker only used to get the pointer
         let mtm = unsafe { MainThreadMarker::new_unchecked() };
@@ -37,7 +37,7 @@ impl<T: IsRetainable> hash::Hash for MainThreadBoundDelegateImpls<T> {
     }
 }
 
-impl<T: IsRetainable> PartialEq for MainThreadBoundDelegateImpls<T> {
+impl<T: IsRetainable + Message> PartialEq for MainThreadBoundDelegateImpls<T> {
     fn eq(&self, other: &Self) -> bool {
         // SAFETY: Marker only used to get the pointer
         let mtm = unsafe { MainThreadMarker::new_unchecked() };
@@ -45,7 +45,7 @@ impl<T: IsRetainable> PartialEq for MainThreadBoundDelegateImpls<T> {
     }
 }
 
-impl<T: IsRetainable> Eq for MainThreadBoundDelegateImpls<T> {}
+impl<T: IsRetainable + Message> Eq for MainThreadBoundDelegateImpls<T> {}
 
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 pub struct VideoMode {
@@ -100,11 +100,9 @@ pub struct MonitorHandle {
 
 impl Clone for MonitorHandle {
     fn clone(&self) -> Self {
-        Self {
-            ui_screen: self
-                .ui_screen
-                .get_on_main(|inner, mtm| MainThreadBound::new(inner.clone(), mtm)),
-        }
+        MainThreadMarker::run_on_main(|mtm| Self {
+            ui_screen: MainThreadBound::new(self.ui_screen.get(mtm).clone(), mtm),
+        })
     }
 }
 
@@ -168,16 +166,16 @@ impl MonitorHandle {
     }
 
     pub fn name(&self) -> Option<String> {
-        self.ui_screen.get_on_main(|ui_screen, mtm| {
+        MainThreadMarker::run_on_main(|mtm| {
             let main = UIScreen::main(mtm);
-            if *ui_screen == main {
+            if *self.ui_screen(mtm) == main {
                 Some("Primary".to_string())
-            } else if *ui_screen == main.mirroredScreen() {
+            } else if *self.ui_screen(mtm) == main.mirroredScreen() {
                 Some("Mirrored".to_string())
             } else {
                 UIScreen::screens(mtm)
                     .iter()
-                    .position(|rhs| rhs == &**ui_screen)
+                    .position(|rhs| rhs == &**self.ui_screen(mtm))
                     .map(|idx| idx.to_string())
             }
         })
@@ -186,31 +184,32 @@ impl MonitorHandle {
     pub fn size(&self) -> PhysicalSize<u32> {
         let bounds = self
             .ui_screen
-            .get_on_main(|ui_screen, _| ui_screen.nativeBounds());
+            .get_on_main(|ui_screen| ui_screen.nativeBounds());
         PhysicalSize::new(bounds.size.width as u32, bounds.size.height as u32)
     }
 
     pub fn position(&self) -> PhysicalPosition<i32> {
         let bounds = self
             .ui_screen
-            .get_on_main(|ui_screen, _| ui_screen.nativeBounds());
+            .get_on_main(|ui_screen| ui_screen.nativeBounds());
         (bounds.origin.x as f64, bounds.origin.y as f64).into()
     }
 
     pub fn scale_factor(&self) -> f64 {
         self.ui_screen
-            .get_on_main(|ui_screen, _| ui_screen.nativeScale()) as f64
+            .get_on_main(|ui_screen| ui_screen.nativeScale()) as f64
     }
 
     pub fn refresh_rate_millihertz(&self) -> Option<u32> {
         Some(
             self.ui_screen
-                .get_on_main(|ui_screen, _| refresh_rate_millihertz(ui_screen)),
+                .get_on_main(|ui_screen| refresh_rate_millihertz(ui_screen)),
         )
     }
 
     pub fn video_modes(&self) -> impl Iterator<Item = VideoMode> {
-        self.ui_screen.get_on_main(|ui_screen, mtm| {
+        MainThreadMarker::run_on_main(|mtm| {
+            let ui_screen = self.ui_screen(mtm);
             // Use Ord impl of RootVideoMode
 
             let modes: BTreeSet<_> = ui_screen
@@ -230,8 +229,12 @@ impl MonitorHandle {
     }
 
     pub fn preferred_video_mode(&self) -> VideoMode {
-        self.ui_screen.get_on_main(|ui_screen, mtm| {
-            VideoMode::new(ui_screen.clone(), ui_screen.preferredMode().unwrap(), mtm)
+        MainThreadMarker::run_on_main(|mtm| {
+            VideoMode::new(
+                self.ui_screen(mtm).clone(),
+                self.ui_screen(mtm).preferredMode().unwrap(),
+                mtm,
+            )
         })
     }
 }
diff --git a/src/platform_impl/ios/view.rs b/src/platform_impl/ios/view.rs
index 17fb3c0e..9b456e6b 100644
--- a/src/platform_impl/ios/view.rs
+++ b/src/platform_impl/ios/view.rs
@@ -1,12 +1,12 @@
 #![allow(clippy::unnecessary_cast)]
 use std::cell::Cell;
-use std::ptr::NonNull;
 
 use icrate::Foundation::{CGFloat, CGRect, MainThreadMarker, NSObject, NSObjectProtocol, NSSet};
-use objc2::declare::{Ivar, IvarDrop};
 use objc2::rc::Id;
 use objc2::runtime::AnyClass;
-use objc2::{declare_class, extern_methods, msg_send, msg_send_id, mutability, ClassType};
+use objc2::{
+    declare_class, extern_methods, msg_send, msg_send_id, mutability, ClassType, DeclaredClass,
+};
 
 use super::app_state::{self, EventWrapper};
 use super::uikit::{
@@ -37,6 +37,8 @@ declare_class!(
         const NAME: &'static str = "WinitUIView";
     }
 
+    impl DeclaredClass for WinitView {}
+
     unsafe impl WinitView {
         #[method(drawRect:)]
         fn draw_rect(&self, rect: CGRect) {
@@ -274,11 +276,7 @@ pub struct ViewControllerState {
 }
 
 declare_class!(
-    pub(crate) struct WinitViewController {
-        state: IvarDrop<Box<ViewControllerState>, "_state">,
-    }
-
-    mod view_controller_ivars;
+    pub(crate) struct WinitViewController;
 
     unsafe impl ClassType for WinitViewController {
         #[inherits(UIResponder, NSObject)]
@@ -287,28 +285,8 @@ declare_class!(
         const NAME: &'static str = "WinitUIViewController";
     }
 
-    unsafe impl WinitViewController {
-        #[method(init)]
-        unsafe fn init(this: *mut Self) -> Option<NonNull<Self>> {
-            let this: Option<&mut Self> = msg_send![super(this), init];
-            this.map(|this| {
-                // These are set in WinitViewController::new, it's just to set them
-                // to _something_.
-                Ivar::write(
-                    &mut this.state,
-                    Box::new(ViewControllerState {
-                        prefers_status_bar_hidden: Cell::new(false),
-                        preferred_status_bar_style: Cell::new(UIStatusBarStyle::Default),
-                        prefers_home_indicator_auto_hidden: Cell::new(false),
-                        supported_orientations: Cell::new(UIInterfaceOrientationMask::All),
-                        preferred_screen_edges_deferring_system_gestures: Cell::new(
-                            UIRectEdge::NONE,
-                        ),
-                    }),
-                );
-                NonNull::from(this)
-            })
-        }
+    impl DeclaredClass for WinitViewController {
+        type Ivars = ViewControllerState;
     }
 
     unsafe impl WinitViewController {
@@ -319,27 +297,27 @@ declare_class!(
 
         #[method(prefersStatusBarHidden)]
         fn prefers_status_bar_hidden(&self) -> bool {
-            self.state.prefers_status_bar_hidden.get()
+            self.ivars().prefers_status_bar_hidden.get()
         }
 
         #[method(preferredStatusBarStyle)]
         fn preferred_status_bar_style(&self) -> UIStatusBarStyle {
-            self.state.preferred_status_bar_style.get()
+            self.ivars().preferred_status_bar_style.get()
         }
 
         #[method(prefersHomeIndicatorAutoHidden)]
         fn prefers_home_indicator_auto_hidden(&self) -> bool {
-            self.state.prefers_home_indicator_auto_hidden.get()
+            self.ivars().prefers_home_indicator_auto_hidden.get()
         }
 
         #[method(supportedInterfaceOrientations)]
         fn supported_orientations(&self) -> UIInterfaceOrientationMask {
-            self.state.supported_orientations.get()
+            self.ivars().supported_orientations.get()
         }
 
         #[method(preferredScreenEdgesDeferringSystemGestures)]
         fn preferred_screen_edges_deferring_system_gestures(&self) -> UIRectEdge {
-            self.state
+            self.ivars()
                 .preferred_screen_edges_deferring_system_gestures
                 .get()
         }
@@ -348,17 +326,17 @@ declare_class!(
 
 impl WinitViewController {
     pub(crate) fn set_prefers_status_bar_hidden(&self, val: bool) {
-        self.state.prefers_status_bar_hidden.set(val);
+        self.ivars().prefers_status_bar_hidden.set(val);
         self.setNeedsStatusBarAppearanceUpdate();
     }
 
     pub(crate) fn set_preferred_status_bar_style(&self, val: UIStatusBarStyle) {
-        self.state.preferred_status_bar_style.set(val);
+        self.ivars().preferred_status_bar_style.set(val);
         self.setNeedsStatusBarAppearanceUpdate();
     }
 
     pub(crate) fn set_prefers_home_indicator_auto_hidden(&self, val: bool) {
-        self.state.prefers_home_indicator_auto_hidden.set(val);
+        self.ivars().prefers_home_indicator_auto_hidden.set(val);
         let os_capabilities = app_state::os_capabilities();
         if os_capabilities.home_indicator_hidden {
             self.setNeedsUpdateOfHomeIndicatorAutoHidden();
@@ -368,7 +346,7 @@ impl WinitViewController {
     }
 
     pub(crate) fn set_preferred_screen_edges_deferring_system_gestures(&self, val: UIRectEdge) {
-        self.state
+        self.ivars()
             .preferred_screen_edges_deferring_system_gestures
             .set(val);
         let os_capabilities = app_state::os_capabilities();
@@ -401,7 +379,7 @@ impl WinitViewController {
                     | UIInterfaceOrientationMask::PortraitUpsideDown
             }
         };
-        self.state.supported_orientations.set(mask);
+        self.ivars().supported_orientations.set(mask);
         UIViewController::attemptRotationToDeviceOrientation();
     }
 
@@ -411,7 +389,15 @@ impl WinitViewController {
         platform_attributes: &PlatformSpecificWindowBuilderAttributes,
         view: &UIView,
     ) -> Id<Self> {
-        let this: Id<Self> = unsafe { msg_send_id![Self::alloc(), init] };
+        // These are set properly below, we just to set them to something in the meantime.
+        let this = Self::alloc().set_ivars(ViewControllerState {
+            prefers_status_bar_hidden: Cell::new(false),
+            preferred_status_bar_style: Cell::new(UIStatusBarStyle::Default),
+            prefers_home_indicator_auto_hidden: Cell::new(false),
+            supported_orientations: Cell::new(UIInterfaceOrientationMask::All),
+            preferred_screen_edges_deferring_system_gestures: Cell::new(UIRectEdge::NONE),
+        });
+        let this: Id<Self> = unsafe { msg_send_id![super(this), init] };
 
         this.set_prefers_status_bar_hidden(platform_attributes.prefers_status_bar_hidden);
 
@@ -446,6 +432,8 @@ declare_class!(
         const NAME: &'static str = "WinitUIWindow";
     }
 
+    impl DeclaredClass for WinitUIWindow {}
+
     unsafe impl WinitUIWindow {
         #[method(becomeKeyWindow)]
         fn become_key_window(&self) {
@@ -518,6 +506,8 @@ declare_class!(
         const NAME: &'static str = "WinitApplicationDelegate";
     }
 
+    impl DeclaredClass for WinitApplicationDelegate {}
+
     // UIApplicationDelegate protocol
     unsafe impl WinitApplicationDelegate {
         #[method(application:didFinishLaunchingWithOptions:)]
diff --git a/src/platform_impl/ios/window.rs b/src/platform_impl/ios/window.rs
index 2f0f8c09..e3480169 100644
--- a/src/platform_impl/ios/window.rs
+++ b/src/platform_impl/ios/window.rs
@@ -520,7 +520,7 @@ impl Window {
     }
 
     pub(crate) fn maybe_wait_on_main<R: Send>(&self, f: impl FnOnce(&Inner) -> R + Send) -> R {
-        self.inner.get_on_main(|inner, _mtm| f(inner))
+        self.inner.get_on_main(|inner| f(inner))
     }
 
     #[cfg(feature = "rwh_06")]
diff --git a/src/platform_impl/macos/app.rs b/src/platform_impl/macos/app.rs
index 326805aa..b1e1fea3 100644
--- a/src/platform_impl/macos/app.rs
+++ b/src/platform_impl/macos/app.rs
@@ -1,14 +1,13 @@
 #![allow(clippy::unnecessary_cast)]
 
 use icrate::Foundation::NSObject;
-use objc2::{declare_class, msg_send, mutability, ClassType};
+use objc2::{declare_class, msg_send, mutability, ClassType, DeclaredClass};
 
 use super::appkit::{NSApplication, NSEvent, NSEventModifierFlags, NSEventType, NSResponder};
 use super::{app_state::AppState, DEVICE_ID};
 use crate::event::{DeviceEvent, ElementState, Event};
 
 declare_class!(
-    #[derive(Debug, PartialEq, Eq, Hash)]
     pub(super) struct WinitApplication;
 
     unsafe impl ClassType for WinitApplication {
@@ -18,6 +17,8 @@ declare_class!(
         const NAME: &'static str = "WinitApplication";
     }
 
+    impl DeclaredClass for WinitApplication {}
+
     unsafe impl WinitApplication {
         // Normally, holding Cmd + any key never sends us a `keyUp` event for that key.
         // Overriding `sendEvent:` like this fixes that. (https://stackoverflow.com/a/15294196)
diff --git a/src/platform_impl/macos/app_delegate.rs b/src/platform_impl/macos/app_delegate.rs
index 4b0991f1..9ab35b4e 100644
--- a/src/platform_impl/macos/app_delegate.rs
+++ b/src/platform_impl/macos/app_delegate.rs
@@ -1,23 +1,20 @@
-use std::ptr::NonNull;
-
 use icrate::Foundation::NSObject;
-use objc2::declare::{IvarBool, IvarEncode};
 use objc2::rc::Id;
 use objc2::runtime::AnyObject;
-use objc2::{declare_class, msg_send, msg_send_id, mutability, ClassType};
+use objc2::{declare_class, msg_send_id, mutability, ClassType, DeclaredClass};
 
 use super::app_state::AppState;
 use super::appkit::NSApplicationActivationPolicy;
 
-declare_class!(
-    #[derive(Debug)]
-    pub(super) struct ApplicationDelegate {
-        activation_policy: IvarEncode<NSApplicationActivationPolicy, "_activation_policy">,
-        default_menu: IvarBool<"_default_menu">,
-        activate_ignoring_other_apps: IvarBool<"_activate_ignoring_other_apps">,
-    }
+#[derive(Debug)]
+pub(super) struct State {
+    activation_policy: NSApplicationActivationPolicy,
+    default_menu: bool,
+    activate_ignoring_other_apps: bool,
+}
 
-    mod ivars;
+declare_class!(
+    pub(super) struct ApplicationDelegate;
 
     unsafe impl ClassType for ApplicationDelegate {
         type Super = NSObject;
@@ -25,30 +22,18 @@ declare_class!(
         const NAME: &'static str = "WinitApplicationDelegate";
     }
 
-    unsafe impl ApplicationDelegate {
-        #[method(initWithActivationPolicy:defaultMenu:activateIgnoringOtherApps:)]
-        unsafe fn init(
-            this: *mut Self,
-            activation_policy: NSApplicationActivationPolicy,
-            default_menu: bool,
-            activate_ignoring_other_apps: bool,
-        ) -> Option<NonNull<Self>> {
-            let this: Option<&mut Self> = unsafe { msg_send![super(this), init] };
-            this.map(|this| {
-                *this.activation_policy = activation_policy;
-                *this.default_menu = default_menu;
-                *this.activate_ignoring_other_apps = activate_ignoring_other_apps;
-                NonNull::from(this)
-            })
-        }
+    impl DeclaredClass for ApplicationDelegate {
+        type Ivars = State;
+    }
 
+    unsafe impl ApplicationDelegate {
         #[method(applicationDidFinishLaunching:)]
         fn did_finish_launching(&self, _sender: Option<&AnyObject>) {
             trace_scope!("applicationDidFinishLaunching:");
             AppState::launched(
-                *self.activation_policy,
-                *self.default_menu,
-                *self.activate_ignoring_other_apps,
+                self.ivars().activation_policy,
+                self.ivars().default_menu,
+                self.ivars().activate_ignoring_other_apps,
             );
         }
 
@@ -67,13 +52,11 @@ impl ApplicationDelegate {
         default_menu: bool,
         activate_ignoring_other_apps: bool,
     ) -> Id<Self> {
-        unsafe {
-            msg_send_id![
-                Self::alloc(),
-                initWithActivationPolicy: activation_policy,
-                defaultMenu: default_menu,
-                activateIgnoringOtherApps: activate_ignoring_other_apps,
-            ]
-        }
+        let this = Self::alloc().set_ivars(State {
+            activation_policy,
+            default_menu,
+            activate_ignoring_other_apps,
+        });
+        unsafe { msg_send_id![super(this), init] }
     }
 }
diff --git a/src/platform_impl/macos/appkit/cursor.rs b/src/platform_impl/macos/appkit/cursor.rs
index de83f0a2..0a2a5e32 100644
--- a/src/platform_impl/macos/appkit/cursor.rs
+++ b/src/platform_impl/macos/appkit/cursor.rs
@@ -1,8 +1,8 @@
 use once_cell::sync::Lazy;
 
-use icrate::ns_string;
 use icrate::Foundation::{
-    NSData, NSDictionary, NSNumber, NSObject, NSObjectProtocol, NSPoint, NSSize, NSString,
+    ns_string, NSData, NSDictionary, NSNumber, NSObject, NSObjectProtocol, NSPoint, NSSize,
+    NSString,
 };
 use objc2::rc::{DefaultId, Id};
 use objc2::runtime::Sel;
diff --git a/src/platform_impl/macos/appkit/screen.rs b/src/platform_impl/macos/appkit/screen.rs
index aa101239..732f06e3 100644
--- a/src/platform_impl/macos/appkit/screen.rs
+++ b/src/platform_impl/macos/appkit/screen.rs
@@ -1,5 +1,6 @@
-use icrate::ns_string;
-use icrate::Foundation::{CGFloat, NSArray, NSDictionary, NSNumber, NSObject, NSRect, NSString};
+use icrate::Foundation::{
+    ns_string, CGFloat, NSArray, NSDictionary, NSNumber, NSObject, NSRect, NSString,
+};
 use objc2::rc::Id;
 use objc2::runtime::AnyObject;
 use objc2::{extern_class, extern_methods, mutability, ClassType};
diff --git a/src/platform_impl/macos/menu.rs b/src/platform_impl/macos/menu.rs
index 978e0bff..5f03e8ed 100644
--- a/src/platform_impl/macos/menu.rs
+++ b/src/platform_impl/macos/menu.rs
@@ -1,5 +1,4 @@
-use icrate::ns_string;
-use icrate::Foundation::{NSProcessInfo, NSString};
+use icrate::Foundation::{ns_string, NSProcessInfo, NSString};
 use objc2::rc::Id;
 use objc2::runtime::Sel;
 use objc2::sel;
diff --git a/src/platform_impl/macos/view.rs b/src/platform_impl/macos/view.rs
index bac77f9e..68f9a032 100644
--- a/src/platform_impl/macos/view.rs
+++ b/src/platform_impl/macos/view.rs
@@ -1,17 +1,16 @@
 #![allow(clippy::unnecessary_cast)]
-use std::boxed::Box;
 use std::cell::{Cell, RefCell};
 use std::collections::{HashMap, VecDeque};
-use std::ptr::NonNull;
 
 use icrate::Foundation::{
     NSArray, NSAttributedString, NSAttributedStringKey, NSCopying, NSMutableAttributedString,
     NSObject, NSObjectProtocol, NSPoint, NSRange, NSRect, NSSize, NSString, NSUInteger,
 };
-use objc2::declare::{Ivar, IvarDrop};
 use objc2::rc::{Id, WeakId};
 use objc2::runtime::{AnyObject, Sel};
-use objc2::{class, declare_class, msg_send, msg_send_id, mutability, sel, ClassType};
+use objc2::{
+    class, declare_class, msg_send, msg_send_id, mutability, sel, ClassType, DeclaredClass,
+};
 
 use super::{
     appkit::{
@@ -140,18 +139,13 @@ pub struct ViewState {
 
     marked_text: RefCell<Id<NSMutableAttributedString>>,
     accepts_first_mouse: bool,
+
+    // Weak reference because the window keeps a strong reference to the view
+    _ns_window: WeakId<WinitWindow>,
 }
 
 declare_class!(
-    #[derive(Debug)]
-    #[allow(non_snake_case)]
-    pub(super) struct WinitView {
-        // Weak reference because the window keeps a strong reference to the view
-        _ns_window: IvarDrop<Box<WeakId<WinitWindow>>, "__ns_window">,
-        state: IvarDrop<Box<ViewState>, "_state">,
-    }
-
-    mod ivars;
+    pub(super) struct WinitView;
 
     unsafe impl ClassType for WinitView {
         #[inherits(NSResponder, NSObject)]
@@ -160,73 +154,33 @@ declare_class!(
         const NAME: &'static str = "WinitView";
     }
 
-    unsafe impl WinitView {
-        #[method(initWithId:acceptsFirstMouse:)]
-        unsafe fn init_with_id(
-            this: *mut Self,
-            window: &WinitWindow,
-            accepts_first_mouse: bool,
-        ) -> Option<NonNull<Self>> {
-            let this: Option<&mut Self> = unsafe { msg_send![super(this), init] };
-            this.map(|this| {
-                let state = ViewState {
-                    accepts_first_mouse,
-                    ..Default::default()
-                };
-
-                Ivar::write(
-                    &mut this._ns_window,
-                    Box::new(WeakId::new(&window.retain())),
-                );
-                Ivar::write(&mut this.state, Box::new(state));
-
-                this.setPostsFrameChangedNotifications(true);
-
-                let notification_center: &AnyObject =
-                    unsafe { msg_send![class!(NSNotificationCenter), defaultCenter] };
-                // About frame change
-                let frame_did_change_notification_name =
-                    NSString::from_str("NSViewFrameDidChangeNotification");
-                #[allow(clippy::let_unit_value)]
-                unsafe {
-                    let _: () = msg_send![
-                        notification_center,
-                        addObserver: &*this,
-                        selector: sel!(frameDidChange:),
-                        name: &*frame_did_change_notification_name,
-                        object: &*this,
-                    ];
-                }
-
-                *this.state.input_source.borrow_mut() = this.current_input_source();
-                NonNull::from(this)
-            })
-        }
+    impl DeclaredClass for WinitView {
+        type Ivars = ViewState;
     }
 
     unsafe impl WinitView {
         #[method(viewDidMoveToWindow)]
         fn view_did_move_to_window(&self) {
             trace_scope!("viewDidMoveToWindow");
-            if let Some(tracking_rect) = self.state.tracking_rect.take() {
+            if let Some(tracking_rect) = self.ivars().tracking_rect.take() {
                 self.removeTrackingRect(tracking_rect);
             }
 
             let rect = self.frame();
             let tracking_rect = self.add_tracking_rect(rect, false);
-            self.state.tracking_rect.set(Some(tracking_rect));
+            self.ivars().tracking_rect.set(Some(tracking_rect));
         }
 
         #[method(frameDidChange:)]
         fn frame_did_change(&self, _event: &NSEvent) {
             trace_scope!("frameDidChange:");
-            if let Some(tracking_rect) = self.state.tracking_rect.take() {
+            if let Some(tracking_rect) = self.ivars().tracking_rect.take() {
                 self.removeTrackingRect(tracking_rect);
             }
 
             let rect = self.frame();
             let tracking_rect = self.add_tracking_rect(rect, false);
-            self.state.tracking_rect.set(Some(tracking_rect));
+            self.ivars().tracking_rect.set(Some(tracking_rect));
 
             // Emit resize event here rather than from windowDidResize because:
             // 1. When a new window is created as a tab, the frame size may change without a window resize occurring.
@@ -241,7 +195,7 @@ declare_class!(
             trace_scope!("drawRect:");
 
             // It's a workaround for https://github.com/rust-windowing/winit/issues/2640, don't replace with `self.window_id()`.
-            if let Some(window) = self._ns_window.load() {
+            if let Some(window) = self.ivars()._ns_window.load() {
                 AppState::handle_redraw(WindowId(window.id()));
             }
 
@@ -270,7 +224,7 @@ declare_class!(
         fn reset_cursor_rects(&self) {
             trace_scope!("resetCursorRects");
             let bounds = self.bounds();
-            let cursor_state = self.state.cursor_state.borrow();
+            let cursor_state = self.ivars().cursor_state.borrow();
             // We correctly invoke `addCursorRect` only from inside `resetCursorRects`
             if cursor_state.visible {
                 self.addCursorRect(bounds, &cursor_state.cursor);
@@ -284,13 +238,13 @@ declare_class!(
         #[method(hasMarkedText)]
         fn has_marked_text(&self) -> bool {
             trace_scope!("hasMarkedText");
-            self.state.marked_text.borrow().length() > 0
+            self.ivars().marked_text.borrow().length() > 0
         }
 
         #[method(markedRange)]
         fn marked_range(&self) -> NSRange {
             trace_scope!("markedRange");
-            let length = self.state.marked_text.borrow().length();
+            let length = self.ivars().marked_text.borrow().length();
             if length > 0 {
                 NSRange::new(0, length)
             } else {
@@ -333,19 +287,19 @@ declare_class!(
             };
 
             // Update marked text.
-            *self.state.marked_text.borrow_mut() = marked_text;
+            *self.ivars().marked_text.borrow_mut() = marked_text;
 
             // Notify IME is active if application still doesn't know it.
-            if self.state.ime_state.get() == ImeState::Disabled {
-                *self.state.input_source.borrow_mut() = self.current_input_source();
+            if self.ivars().ime_state.get() == ImeState::Disabled {
+                *self.ivars().input_source.borrow_mut() = self.current_input_source();
                 self.queue_event(WindowEvent::Ime(Ime::Enabled));
             }
 
             if self.hasMarkedText() {
-                self.state.ime_state.set(ImeState::Preedit);
+                self.ivars().ime_state.set(ImeState::Preedit);
             } else {
                 // In case the preedit was cleared, set IME into the Ground state.
-                self.state.ime_state.set(ImeState::Ground);
+                self.ivars().ime_state.set(ImeState::Ground);
             }
 
             // Empty string basically means that there's no preedit, so indicate that by sending
@@ -363,15 +317,15 @@ declare_class!(
         #[method(unmarkText)]
         fn unmark_text(&self) {
             trace_scope!("unmarkText");
-            *self.state.marked_text.borrow_mut() = NSMutableAttributedString::new();
+            *self.ivars().marked_text.borrow_mut() = NSMutableAttributedString::new();
 
             let input_context = self.inputContext().expect("input context");
             input_context.discardMarkedText();
 
             self.queue_event(WindowEvent::Ime(Ime::Preedit(String::new(), None)));
             if self.is_ime_enabled() {
-                // Leave the Preedit self.state
-                self.state.ime_state.set(ImeState::Ground);
+                // Leave the Preedit self.ivars()
+                self.ivars().ime_state.set(ImeState::Ground);
             } else {
                 warn!("Expected to have IME enabled when receiving unmarkText");
             }
@@ -410,9 +364,9 @@ declare_class!(
             let content_rect = window.contentRectForFrameRect(window.frame());
             let base_x = content_rect.origin.x as f64;
             let base_y = (content_rect.origin.y + content_rect.size.height) as f64;
-            let x = base_x + self.state.ime_position.get().x;
-            let y = base_y - self.state.ime_position.get().y;
-            let LogicalSize { width, height } = self.state.ime_size.get();
+            let x = base_x + self.ivars().ime_position.get().x;
+            let y = base_y - self.ivars().ime_position.get().y;
+            let LogicalSize { width, height } = self.ivars().ime_size.get();
             NSRect::new(NSPoint::new(x as _, y as _), NSSize::new(width, height))
         }
 
@@ -437,7 +391,7 @@ declare_class!(
             if self.hasMarkedText() && self.is_ime_enabled() && !is_control {
                 self.queue_event(WindowEvent::Ime(Ime::Preedit(String::new(), None)));
                 self.queue_event(WindowEvent::Ime(Ime::Commit(string)));
-                self.state.ime_state.set(ImeState::Commited);
+                self.ivars().ime_state.set(ImeState::Commited);
             }
         }
 
@@ -449,15 +403,15 @@ declare_class!(
             // We shouldn't forward any character from just commited text, since we'll end up sending
             // it twice with some IMEs like Korean one. We'll also always send `Enter` in that case,
             // which is not desired given it was used to confirm IME input.
-            if self.state.ime_state.get() == ImeState::Commited {
+            if self.ivars().ime_state.get() == ImeState::Commited {
                 return;
             }
 
-            self.state.forward_key_to_app.set(true);
+            self.ivars().forward_key_to_app.set(true);
 
-            if self.hasMarkedText() && self.state.ime_state.get() == ImeState::Preedit {
+            if self.hasMarkedText() && self.ivars().ime_state.get() == ImeState::Preedit {
                 // Leave preedit so that we also report the key-up for this key.
-                self.state.ime_state.set(ImeState::Ground);
+                self.ivars().ime_state.set(ImeState::Ground);
             }
         }
     }
@@ -467,19 +421,19 @@ declare_class!(
         fn key_down(&self, event: &NSEvent) {
             trace_scope!("keyDown:");
             {
-                let mut prev_input_source = self.state.input_source.borrow_mut();
+                let mut prev_input_source = self.ivars().input_source.borrow_mut();
                 let current_input_source = self.current_input_source();
                 if *prev_input_source != current_input_source && self.is_ime_enabled() {
                     *prev_input_source = current_input_source;
                     drop(prev_input_source);
-                    self.state.ime_state.set(ImeState::Disabled);
+                    self.ivars().ime_state.set(ImeState::Disabled);
                     self.queue_event(WindowEvent::Ime(Ime::Disabled));
                 }
             }
 
             // Get the characters from the event.
-            let old_ime_state = self.state.ime_state.get();
-            self.state.forward_key_to_app.set(false);
+            let old_ime_state = self.ivars().ime_state.get();
+            self.ivars().forward_key_to_app.set(false);
             let event = replace_event(event, self.window().option_as_alt());
 
             // The `interpretKeyEvents` function might call
@@ -488,31 +442,31 @@ declare_class!(
             // we must send the `KeyboardInput` event during IME if it triggered
             // `doCommandBySelector`. (doCommandBySelector means that the keyboard input
             // is not handled by IME and should be handled by the application)
-            if self.state.ime_allowed.get() {
+            if self.ivars().ime_allowed.get() {
                 let events_for_nsview = NSArray::from_slice(&[&*event]);
                 unsafe { self.interpretKeyEvents(&events_for_nsview) };
 
                 // If the text was commited we must treat the next keyboard event as IME related.
-                if self.state.ime_state.get() == ImeState::Commited {
+                if self.ivars().ime_state.get() == ImeState::Commited {
                     // Remove any marked text, so normal input can continue.
-                    *self.state.marked_text.borrow_mut() = NSMutableAttributedString::new();
+                    *self.ivars().marked_text.borrow_mut() = NSMutableAttributedString::new();
                 }
             }
 
             self.update_modifiers(&event, false);
 
-            let had_ime_input = match self.state.ime_state.get() {
+            let had_ime_input = match self.ivars().ime_state.get() {
                 ImeState::Commited => {
                     // Allow normal input after the commit.
-                    self.state.ime_state.set(ImeState::Ground);
+                    self.ivars().ime_state.set(ImeState::Ground);
                     true
                 }
                 ImeState::Preedit => true,
                 // `key_down` could result in preedit clear, so compare old and current state.
-                _ => old_ime_state != self.state.ime_state.get(),
+                _ => old_ime_state != self.ivars().ime_state.get(),
             };
 
-            if !had_ime_input || self.state.forward_key_to_app.get() {
+            if !had_ime_input || self.ivars().forward_key_to_app.get() {
                 let key_event = create_key_event(&event, true, event.is_a_repeat(), None);
                 self.queue_event(WindowEvent::KeyboardInput {
                     device_id: DEVICE_ID,
@@ -531,7 +485,7 @@ declare_class!(
 
             // We want to send keyboard input when we are currently in the ground state.
             if matches!(
-                self.state.ime_state.get(),
+                self.ivars().ime_state.get(),
                 ImeState::Ground | ImeState::Disabled
             ) {
                 self.queue_event(WindowEvent::KeyboardInput {
@@ -792,20 +746,40 @@ declare_class!(
         #[method(acceptsFirstMouse:)]
         fn accepts_first_mouse(&self, _event: &NSEvent) -> bool {
             trace_scope!("acceptsFirstMouse:");
-            self.state.accepts_first_mouse
+            self.ivars().accepts_first_mouse
         }
     }
 );
 
 impl WinitView {
     pub(super) fn new(window: &WinitWindow, accepts_first_mouse: bool) -> Id<Self> {
+        let this = Self::alloc().set_ivars(ViewState {
+            accepts_first_mouse,
+            _ns_window: WeakId::new(&window.retain()),
+            ..Default::default()
+        });
+        let this: Id<Self> = unsafe { msg_send_id![super(this), init] };
+
+        this.setPostsFrameChangedNotifications(true);
+        let notification_center: &AnyObject =
+            unsafe { msg_send![class!(NSNotificationCenter), defaultCenter] };
+        // About frame change
+        let frame_did_change_notification_name =
+            NSString::from_str("NSViewFrameDidChangeNotification");
+        #[allow(clippy::let_unit_value)]
         unsafe {
-            msg_send_id![
-                Self::alloc(),
-                initWithId: window,
-                acceptsFirstMouse: accepts_first_mouse,
-            ]
+            let _: () = msg_send![
+                notification_center,
+                addObserver: &*this,
+                selector: sel!(frameDidChange:),
+                name: &*frame_did_change_notification_name,
+                object: &*this,
+            ];
         }
+
+        *this.ivars().input_source.borrow_mut() = this.current_input_source();
+
+        this
     }
 
     fn window(&self) -> Id<WinitWindow> {
@@ -814,7 +788,10 @@ impl WinitView {
         // (which is incompatible with `frameDidChange:`)
         //
         // unsafe { msg_send_id![self, window] }
-        self._ns_window.load().expect("view to have a window")
+        self.ivars()
+            ._ns_window
+            .load()
+            .expect("view to have a window")
     }
 
     fn window_id(&self) -> WindowId {
@@ -842,7 +819,7 @@ impl WinitView {
     }
 
     fn is_ime_enabled(&self) -> bool {
-        !matches!(self.state.ime_state.get(), ImeState::Disabled)
+        !matches!(self.ivars().ime_state.get(), ImeState::Disabled)
     }
 
     fn current_input_source(&self) -> String {
@@ -854,7 +831,7 @@ impl WinitView {
     }
 
     pub(super) fn set_cursor_icon(&self, icon: Id<NSCursor>) {
-        let mut cursor_state = self.state.cursor_state.borrow_mut();
+        let mut cursor_state = self.ivars().cursor_state.borrow_mut();
         cursor_state.cursor = icon;
     }
 
@@ -862,7 +839,7 @@ impl WinitView {
     ///
     /// Returns whether the state changed.
     pub(super) fn set_cursor_visible(&self, visible: bool) -> bool {
-        let mut cursor_state = self.state.cursor_state.borrow_mut();
+        let mut cursor_state = self.ivars().cursor_state.borrow_mut();
         if visible != cursor_state.visible {
             cursor_state.visible = visible;
             true
@@ -872,19 +849,19 @@ impl WinitView {
     }
 
     pub(super) fn set_ime_allowed(&self, ime_allowed: bool) {
-        if self.state.ime_allowed.get() == ime_allowed {
+        if self.ivars().ime_allowed.get() == ime_allowed {
             return;
         }
-        self.state.ime_allowed.set(ime_allowed);
-        if self.state.ime_allowed.get() {
+        self.ivars().ime_allowed.set(ime_allowed);
+        if self.ivars().ime_allowed.get() {
             return;
         }
 
         // Clear markedText
-        *self.state.marked_text.borrow_mut() = NSMutableAttributedString::new();
+        *self.ivars().marked_text.borrow_mut() = NSMutableAttributedString::new();
 
-        if self.state.ime_state.get() != ImeState::Disabled {
-            self.state.ime_state.set(ImeState::Disabled);
+        if self.ivars().ime_state.get() != ImeState::Disabled {
+            self.ivars().ime_state.set(ImeState::Disabled);
             self.queue_event(WindowEvent::Ime(Ime::Disabled));
         }
     }
@@ -894,17 +871,17 @@ impl WinitView {
         position: LogicalPosition<f64>,
         size: LogicalSize<f64>,
     ) {
-        self.state.ime_position.set(position);
-        self.state.ime_size.set(size);
+        self.ivars().ime_position.set(position);
+        self.ivars().ime_size.set(size);
         let input_context = self.inputContext().expect("input context");
         input_context.invalidateCharacterCoordinates();
     }
 
     /// Reset modifiers and emit a synthetic ModifiersChanged event if deemed necessary.
     pub(super) fn reset_modifiers(&self) {
-        if !self.state.modifiers.get().state().is_empty() {
-            self.state.modifiers.set(Modifiers::default());
-            self.queue_event(WindowEvent::ModifiersChanged(self.state.modifiers.get()));
+        if !self.ivars().modifiers.get().state().is_empty() {
+            self.ivars().modifiers.set(Modifiers::default());
+            self.queue_event(WindowEvent::ModifiersChanged(self.ivars().modifiers.get()));
         }
     }
 
@@ -913,8 +890,8 @@ impl WinitView {
         use ElementState::{Pressed, Released};
 
         let current_modifiers = event_mods(ns_event);
-        let prev_modifiers = self.state.modifiers.get();
-        self.state.modifiers.set(current_modifiers);
+        let prev_modifiers = self.ivars().modifiers.get();
+        self.ivars().modifiers.set(current_modifiers);
 
         // This function was called form the flagsChanged event, which is triggered
         // when the user presses/releases a modifier even if the same kind of modifier
@@ -943,7 +920,7 @@ impl WinitView {
                 event.location = code_to_location(physical_key);
                 let location_mask = ModLocationMask::from_location(event.location);
 
-                let mut phys_mod_state = self.state.phys_modifiers.borrow_mut();
+                let mut phys_mod_state = self.ivars().phys_modifiers.borrow_mut();
                 let phys_mod = phys_mod_state
                     .entry(key)
                     .or_insert(ModLocationMask::empty());
@@ -1021,7 +998,7 @@ impl WinitView {
             return;
         }
 
-        self.queue_event(WindowEvent::ModifiersChanged(self.state.modifiers.get()));
+        self.queue_event(WindowEvent::ModifiersChanged(self.ivars().modifiers.get()));
     }
 
     fn mouse_click(&self, event: &NSEvent, button_state: ElementState) {
diff --git a/src/platform_impl/macos/window.rs b/src/platform_impl/macos/window.rs
index 91918216..06ba38bd 100644
--- a/src/platform_impl/macos/window.rs
+++ b/src/platform_impl/macos/window.rs
@@ -3,8 +3,6 @@
 use std::collections::VecDeque;
 use std::f64;
 use std::ops;
-use std::os::raw::c_void;
-use std::ptr::NonNull;
 use std::sync::{Mutex, MutexGuard};
 
 use crate::{
@@ -36,9 +34,8 @@ use icrate::Foundation::{
     CGFloat, MainThreadBound, MainThreadMarker, NSArray, NSCopying, NSInteger, NSObject, NSPoint,
     NSRect, NSSize, NSString,
 };
-use objc2::declare::{Ivar, IvarDrop};
 use objc2::rc::{autoreleasepool, Id};
-use objc2::{declare_class, msg_send, msg_send_id, mutability, sel, ClassType};
+use objc2::{declare_class, msg_send, msg_send_id, mutability, sel, ClassType, DeclaredClass};
 
 use super::appkit::{
     NSApp, NSAppKitVersion, NSAppearance, NSApplicationPresentationOptions, NSBackingStoreType,
@@ -58,7 +55,7 @@ pub(crate) struct Window {
 impl Drop for Window {
     fn drop(&mut self) {
         self.window
-            .get_on_main(|window, _| autoreleasepool(|_| window.close()))
+            .get_on_main(|window| autoreleasepool(|_| window.close()))
     }
 }
 
@@ -86,7 +83,7 @@ impl Window {
         &self,
         f: impl FnOnce(&WinitWindow) -> R + Send,
     ) -> R {
-        self.window.get_on_main(|window, _mtm| f(window))
+        self.window.get_on_main(|window| f(window))
     }
 
     #[cfg(feature = "rwh_06")]
@@ -159,12 +156,7 @@ impl Default for PlatformSpecificWindowBuilderAttributes {
 
 declare_class!(
     #[derive(Debug)]
-    pub struct WinitWindow {
-        // TODO: Fix unnecessary boxing here
-        shared_state: IvarDrop<Box<Mutex<SharedState>>, "_shared_state">,
-    }
-
-    mod ivars;
+    pub struct WinitWindow;
 
     unsafe impl ClassType for WinitWindow {
         #[inherits(NSResponder, NSObject)]
@@ -173,38 +165,8 @@ declare_class!(
         const NAME: &'static str = "WinitWindow";
     }
 
-    unsafe impl WinitWindow {
-        #[method(initWithContentRect:styleMask:state:)]
-        unsafe fn init(
-            this: *mut Self,
-            frame: NSRect,
-            mask: NSWindowStyleMask,
-            state: *mut c_void,
-        ) -> Option<NonNull<Self>> {
-            let this: Option<&mut Self> = unsafe {
-                msg_send![
-                    super(this),
-                    initWithContentRect: frame,
-                    styleMask: mask,
-                    backing: NSBackingStoreType::NSBackingStoreBuffered,
-                    defer: false,
-                ]
-            };
-
-            this.map(|this| {
-                // SAFETY: The pointer originally came from `Box::into_raw`.
-                Ivar::write(&mut this.shared_state, unsafe {
-                    Box::from_raw(state as *mut Mutex<SharedState>)
-                });
-
-                // It is imperative to correct memory management that we
-                // disable the extra release that would otherwise happen when
-                // calling `clone` on the window.
-                this.setReleasedWhenClosed(false);
-
-                NonNull::from(this)
-            })
-        }
+    impl DeclaredClass for WinitWindow {
+        type Ivars = Mutex<SharedState>;
     }
 
     unsafe impl WinitWindow {
@@ -384,18 +346,23 @@ impl WinitWindow {
                 ..Default::default()
             };
 
-            // Pass the state through FFI to the method declared on the class
-            let state_ptr: *mut c_void = Box::into_raw(Box::new(Mutex::new(state))).cast();
+            let this = WinitWindow::alloc().set_ivars(Mutex::new(state));
             let this: Option<Id<Self>> = unsafe {
                 msg_send_id![
-                    WinitWindow::alloc(),
+                    super(this),
                     initWithContentRect: frame,
                     styleMask: masks,
-                    state: state_ptr,
+                    backing: NSBackingStoreType::NSBackingStoreBuffered,
+                    defer: false,
                 ]
             };
             let this = this?;
 
+            // It is very important for correct memory management that we
+            // disable the extra release that would otherwise happen when
+            // calling `close` on the window.
+            this.setReleasedWhenClosed(false);
+
             let resize_increments = match attrs
                 .resize_increments
                 .map(|i| i.to_logical::<f64>(this.scale_factor()))
@@ -576,7 +543,7 @@ impl WinitWindow {
         &self,
         called_from_fn: &'static str,
     ) -> SharedStateMutexGuard<'_> {
-        SharedStateMutexGuard::new(self.shared_state.lock().unwrap(), called_from_fn)
+        SharedStateMutexGuard::new(self.ivars().lock().unwrap(), called_from_fn)
     }
 
     fn set_style_mask(&self, mask: NSWindowStyleMask) {
diff --git a/src/platform_impl/macos/window_delegate.rs b/src/platform_impl/macos/window_delegate.rs
index fb6df1b4..e5a62dec 100644
--- a/src/platform_impl/macos/window_delegate.rs
+++ b/src/platform_impl/macos/window_delegate.rs
@@ -1,12 +1,13 @@
 #![allow(clippy::unnecessary_cast)]
 use std::cell::Cell;
-use std::ptr::{self, NonNull};
+use std::ptr;
 
 use icrate::Foundation::{NSArray, NSObject, NSSize, NSString};
-use objc2::declare::{Ivar, IvarDrop};
 use objc2::rc::{autoreleasepool, Id};
 use objc2::runtime::AnyObject;
-use objc2::{class, declare_class, msg_send, msg_send_id, mutability, sel, ClassType};
+use objc2::{
+    class, declare_class, msg_send, msg_send_id, mutability, sel, ClassType, DeclaredClass,
+};
 
 use super::appkit::{
     NSApplicationPresentationOptions, NSFilenamesPboardType, NSPasteboard, NSWindowOcclusionState,
@@ -24,7 +25,9 @@ use crate::{
 };
 
 #[derive(Debug)]
-pub struct State {
+pub(crate) struct State {
+    window: Id<WinitWindow>,
+
     // This is set when WindowBuilder::with_fullscreen was set,
     // see comments of `window_did_fail_to_enter_fullscreen`
     initial_fullscreen: Cell<bool>,
@@ -37,17 +40,7 @@ pub struct State {
 }
 
 declare_class!(
-    #[derive(Debug)]
-    pub(crate) struct WinitWindowDelegate {
-        window: IvarDrop<Id<WinitWindow>, "_window">,
-
-        // TODO: It may be possible for delegate methods to be called
-        // asynchronously, causing data races panics?
-        // TODO: Remove unnecessary boxing here
-        state: IvarDrop<Box<State>, "_state">,
-    }
-
-    mod ivars;
+    pub(crate) struct WinitWindowDelegate;
 
     unsafe impl ClassType for WinitWindowDelegate {
         type Super = NSObject;
@@ -55,50 +48,8 @@ declare_class!(
         const NAME: &'static str = "WinitWindowDelegate";
     }
 
-    unsafe impl WinitWindowDelegate {
-        #[method(initWithWindow:initialFullscreen:)]
-        unsafe fn init_with_winit(
-            this: *mut Self,
-            window: &WinitWindow,
-            initial_fullscreen: bool,
-        ) -> Option<NonNull<Self>> {
-            let this: Option<&mut Self> = unsafe { msg_send![super(this), init] };
-            this.map(|this| {
-                let scale_factor = window.scale_factor();
-
-                Ivar::write(&mut this.window, window.retain());
-                Ivar::write(
-                    &mut this.state,
-                    Box::new(State {
-                        initial_fullscreen: Cell::new(initial_fullscreen),
-                        previous_position: Cell::new(None),
-                        previous_scale_factor: Cell::new(scale_factor),
-                    }),
-                );
-
-                if scale_factor != 1.0 {
-                    this.queue_static_scale_factor_changed_event();
-                }
-                this.window.setDelegate(Some(this));
-
-                // Enable theme change event
-                let notification_center: Id<AnyObject> =
-                    unsafe { msg_send_id![class!(NSDistributedNotificationCenter), defaultCenter] };
-                let notification_name =
-                    NSString::from_str("AppleInterfaceThemeChangedNotification");
-                let _: () = unsafe {
-                    msg_send![
-                        &notification_center,
-                        addObserver: &*this
-                        selector: sel!(effectiveAppearanceDidChange:)
-                        name: &*notification_name
-                        object: ptr::null::<AnyObject>()
-                    ]
-                };
-
-                NonNull::from(this)
-            })
-        }
+    impl DeclaredClass for WinitWindowDelegate {
+        type Ivars = State;
     }
 
     // NSWindowDelegate + NSDraggingDestination protocols
@@ -117,7 +68,7 @@ declare_class!(
             autoreleasepool(|_| {
                 // Since El Capitan, we need to be careful that delegate methods can't
                 // be called after the window closes.
-                self.window.setDelegate(None);
+                self.ivars().window.setDelegate(None);
             });
             self.queue_event(WindowEvent::Destroyed);
         }
@@ -134,16 +85,19 @@ declare_class!(
             trace_scope!("windowWillStartLiveResize:");
 
             let increments = self
+                .ivars()
                 .window
                 .lock_shared_state("window_will_enter_fullscreen")
                 .resize_increments;
-            self.window.set_resize_increments_inner(increments);
+            self.ivars().window.set_resize_increments_inner(increments);
         }
 
         #[method(windowDidEndLiveResize:)]
         fn window_did_end_live_resize(&self, _: Option<&AnyObject>) {
             trace_scope!("windowDidEndLiveResize:");
-            self.window.set_resize_increments_inner(NSSize::new(1., 1.));
+            self.ivars()
+                .window
+                .set_resize_increments_inner(NSSize::new(1., 1.));
         }
 
         // This won't be triggered if the move was part of a resize.
@@ -177,7 +131,7 @@ declare_class!(
             // NSWindowDelegate, and as a result a tracked modifiers state can quite
             // easily fall out of synchrony with reality.  This requires us to emit
             // a synthetic ModifiersChanged event when we lose focus.
-            self.window.view().reset_modifiers();
+            self.ivars().window.view().reset_modifiers();
 
             self.queue_event(WindowEvent::Focused(false));
         }
@@ -246,9 +200,10 @@ declare_class!(
             trace_scope!("windowWillEnterFullScreen:");
 
             let mut shared_state = self
+                .ivars()
                 .window
                 .lock_shared_state("window_will_enter_fullscreen");
-            shared_state.maximized = self.window.is_zoomed();
+            shared_state.maximized = self.ivars().window.is_zoomed();
             let fullscreen = shared_state.fullscreen.as_ref();
             match fullscreen {
                 // Exclusive mode sets the state in `set_fullscreen` as the user
@@ -262,7 +217,7 @@ declare_class!(
                 // Otherwise, we must've reached fullscreen by the user clicking
                 // on the green fullscreen button. Update state!
                 None => {
-                    let current_monitor = self.window.current_monitor_inner();
+                    let current_monitor = self.ivars().window.current_monitor_inner();
                     shared_state.fullscreen = Some(Fullscreen::Borderless(current_monitor))
                 }
             }
@@ -274,7 +229,10 @@ declare_class!(
         fn window_will_exit_fullscreen(&self, _: Option<&AnyObject>) {
             trace_scope!("windowWillExitFullScreen:");
 
-            let mut shared_state = self.window.lock_shared_state("window_will_exit_fullscreen");
+            let mut shared_state = self
+                .ivars()
+                .window
+                .lock_shared_state("window_will_exit_fullscreen");
             shared_state.in_fullscreen_transition = true;
         }
 
@@ -295,6 +253,7 @@ declare_class!(
             // user-provided options are ignored in exclusive fullscreen.
             let mut options = proposed_options;
             let shared_state = self
+                .ivars()
                 .window
                 .lock_shared_state("window_will_use_fullscreen_presentation_options");
             if let Some(Fullscreen::Exclusive(_)) = shared_state.fullscreen {
@@ -310,13 +269,16 @@ declare_class!(
         #[method(windowDidEnterFullScreen:)]
         fn window_did_enter_fullscreen(&self, _: Option<&AnyObject>) {
             trace_scope!("windowDidEnterFullScreen:");
-            self.state.initial_fullscreen.set(false);
-            let mut shared_state = self.window.lock_shared_state("window_did_enter_fullscreen");
+            self.ivars().initial_fullscreen.set(false);
+            let mut shared_state = self
+                .ivars()
+                .window
+                .lock_shared_state("window_did_enter_fullscreen");
             shared_state.in_fullscreen_transition = false;
             let target_fullscreen = shared_state.target_fullscreen.take();
             drop(shared_state);
             if let Some(target_fullscreen) = target_fullscreen {
-                self.window.set_fullscreen(target_fullscreen);
+                self.ivars().window.set_fullscreen(target_fullscreen);
             }
         }
 
@@ -325,13 +287,16 @@ declare_class!(
         fn window_did_exit_fullscreen(&self, _: Option<&AnyObject>) {
             trace_scope!("windowDidExitFullScreen:");
 
-            self.window.restore_state_from_fullscreen();
-            let mut shared_state = self.window.lock_shared_state("window_did_exit_fullscreen");
+            self.ivars().window.restore_state_from_fullscreen();
+            let mut shared_state = self
+                .ivars()
+                .window
+                .lock_shared_state("window_did_exit_fullscreen");
             shared_state.in_fullscreen_transition = false;
             let target_fullscreen = shared_state.target_fullscreen.take();
             drop(shared_state);
             if let Some(target_fullscreen) = target_fullscreen {
-                self.window.set_fullscreen(target_fullscreen);
+                self.ivars().window.set_fullscreen(target_fullscreen);
             }
         }
 
@@ -355,22 +320,23 @@ declare_class!(
         fn window_did_fail_to_enter_fullscreen(&self, _: Option<&AnyObject>) {
             trace_scope!("windowDidFailToEnterFullScreen:");
             let mut shared_state = self
+                .ivars()
                 .window
                 .lock_shared_state("window_did_fail_to_enter_fullscreen");
             shared_state.in_fullscreen_transition = false;
             shared_state.target_fullscreen = None;
-            if self.state.initial_fullscreen.get() {
+            if self.ivars().initial_fullscreen.get() {
                 #[allow(clippy::let_unit_value)]
                 unsafe {
                     let _: () = msg_send![
-                        &*self.window,
+                        &*self.ivars().window,
                         performSelector: sel!(toggleFullScreen:),
                         withObject: ptr::null::<AnyObject>(),
                         afterDelay: 0.5,
                     ];
                 };
             } else {
-                self.window.restore_state_from_fullscreen();
+                self.ivars().window.restore_state_from_fullscreen();
             }
         }
 
@@ -380,6 +346,7 @@ declare_class!(
             trace_scope!("windowDidChangeOcclusionState:");
             self.queue_event(WindowEvent::Occluded(
                 !self
+                    .ivars()
                     .window
                     .occlusionState()
                     .contains(NSWindowOcclusionState::NSWindowOcclusionStateVisible),
@@ -404,6 +371,7 @@ declare_class!(
         fn effective_appearance_did_changed_on_main_thread(&self, _: Option<&AnyObject>) {
             let theme = get_ns_theme();
             let mut shared_state = self
+                .ivars()
                 .window
                 .lock_shared_state("effective_appearance_did_change");
             let current_theme = shared_state.current_theme;
@@ -418,12 +386,13 @@ declare_class!(
         fn window_did_change_screen(&self, _: Option<&AnyObject>) {
             trace_scope!("windowDidChangeScreen:");
             let is_simple_fullscreen = self
+                .ivars()
                 .window
                 .lock_shared_state("window_did_change_screen")
                 .is_simple_fullscreen;
             if is_simple_fullscreen {
-                if let Some(screen) = self.window.screen() {
-                    self.window.setFrame_display(screen.frame(), true);
+                if let Some(screen) = self.ivars().window.screen() {
+                    self.ivars().window.setFrame_display(screen.frame(), true);
                 }
             }
         }
@@ -432,52 +401,74 @@ declare_class!(
 
 impl WinitWindowDelegate {
     pub fn new(window: &WinitWindow, initial_fullscreen: bool) -> Id<Self> {
-        unsafe {
-            msg_send_id![
-                Self::alloc(),
-                initWithWindow: window,
-                initialFullscreen: initial_fullscreen,
-            ]
+        let scale_factor = window.scale_factor();
+        let this = Self::alloc().set_ivars(State {
+            window: window.retain(),
+            initial_fullscreen: Cell::new(initial_fullscreen),
+            previous_position: Cell::new(None),
+            previous_scale_factor: Cell::new(scale_factor),
+        });
+        let this: Id<Self> = unsafe { msg_send_id![super(this), init] };
+
+        if scale_factor != 1.0 {
+            this.queue_static_scale_factor_changed_event();
         }
+        this.ivars().window.setDelegate(Some(&this));
+
+        // Enable theme change event
+        let notification_center: Id<AnyObject> =
+            unsafe { msg_send_id![class!(NSDistributedNotificationCenter), defaultCenter] };
+        let notification_name = NSString::from_str("AppleInterfaceThemeChangedNotification");
+        let _: () = unsafe {
+            msg_send![
+                &notification_center,
+                addObserver: &*this
+                selector: sel!(effectiveAppearanceDidChange:)
+                name: &*notification_name
+                object: ptr::null::<AnyObject>()
+            ]
+        };
+
+        this
     }
 
     pub(crate) fn queue_event(&self, event: WindowEvent) {
         let event = Event::WindowEvent {
-            window_id: WindowId(self.window.id()),
+            window_id: WindowId(self.ivars().window.id()),
             event,
         };
         AppState::queue_event(event);
     }
 
     fn queue_static_scale_factor_changed_event(&self) {
-        let scale_factor = self.window.scale_factor();
-        if scale_factor == self.state.previous_scale_factor.get() {
+        let scale_factor = self.ivars().window.scale_factor();
+        if scale_factor == self.ivars().previous_scale_factor.get() {
             return;
         };
 
-        self.state.previous_scale_factor.set(scale_factor);
+        self.ivars().previous_scale_factor.set(scale_factor);
         let suggested_size = self.view_size();
         AppState::queue_static_scale_factor_changed_event(
-            self.window.clone(),
+            self.ivars().window.clone(),
             suggested_size.to_physical(scale_factor),
             scale_factor,
         );
     }
 
     fn emit_move_event(&self) {
-        let rect = self.window.frame();
+        let rect = self.ivars().window.frame();
         let x = rect.origin.x as f64;
         let y = util::bottom_left_to_top_left(rect);
-        if self.state.previous_position.get() != Some((x, y)) {
-            self.state.previous_position.set(Some((x, y)));
-            let scale_factor = self.window.scale_factor();
+        if self.ivars().previous_position.get() != Some((x, y)) {
+            self.ivars().previous_position.set(Some((x, y)));
+            let scale_factor = self.ivars().window.scale_factor();
             let physical_pos = LogicalPosition::<f64>::from((x, y)).to_physical(scale_factor);
             self.queue_event(WindowEvent::Moved(physical_pos));
         }
     }
 
     fn view_size(&self) -> LogicalSize<f64> {
-        let size = self.window.contentView().frame().size;
+        let size = self.ivars().window.contentView().frame().size;
         LogicalSize::new(size.width as f64, size.height as f64)
     }
 }