diff --git a/src/buffer.rs b/src/buffer.rs
index 14684f7..9d8b49a 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -426,6 +426,11 @@ impl Buffer {
     fn resolve_dirty(&mut self) -> bool {
         let dirty = self.dirty;
         if dirty.is_empty() {
+            // individual lines may have been externally invalidated
+            if self.lines.iter().any(|line| line.needs_reshaping()) {
+                self.redraw = true;
+                return true;
+            }
             return false;
         }
 
diff --git a/src/buffer_line.rs b/src/buffer_line.rs
index 0f3933c..4548604 100644
--- a/src/buffer_line.rs
+++ b/src/buffer_line.rs
@@ -236,6 +236,10 @@ impl BufferLine {
         self.shape_opt.get()
     }
 
+    pub const fn needs_reshaping(&self) -> bool {
+        self.shape_opt.is_invalidated() || self.layout_opt.is_invalidated()
+    }
+
     /// Layout line, will cache results
     #[allow(clippy::missing_panics_doc)]
     pub fn layout(
diff --git a/src/cached.rs b/src/cached.rs
index 51079e8..6aaa932 100644
--- a/src/cached.rs
+++ b/src/cached.rs
@@ -42,6 +42,11 @@ impl<T: Clone + Debug> Cached<T> {
         }
     }
 
+    /// Checks if the value was previously cached but has been invalidated.
+    pub const fn is_invalidated(&self) -> bool {
+        matches!(self, Self::Unused(_))
+    }
+
     /// Takes the buffered value if in state `Self::Unused`.
     pub fn take_unused(&mut self) -> Option<T> {
         if matches!(*self, Self::Unused(_)) {