diff --git a/crates/buffers/src/lib.rs b/crates/buffers/src/lib.rs
index 3079b34..c059e9c 100644
--- a/crates/buffers/src/lib.rs
+++ b/crates/buffers/src/lib.rs
@@ -3,16 +3,16 @@
 //
 // Not useful outside of librqbit.
 
-use std::marker::PhantomData;
-
-use serde::Deserializer;
+use serde::Deserialize;
 
 use clone_to_owned::CloneToOwned;
 
-#[derive(Default, PartialEq, Eq, Hash, Clone, PartialOrd, Ord)]
+#[derive(Default, Deserialize, PartialEq, Eq, Hash, Clone, PartialOrd, Ord)]
+#[serde(transparent)]
 pub struct ByteBufOwned(pub Box<[u8]>);
 
-#[derive(Default, PartialEq, Eq, Hash, Clone, PartialOrd, Ord)]
+#[derive(Default, Deserialize, PartialEq, Eq, Hash, Clone, PartialOrd, Ord)]
+#[serde(transparent)]
 pub struct ByteBuf<'a>(pub &'a [u8]);
 
 pub trait ByteBufT {
@@ -170,54 +170,3 @@ impl serde::ser::Serialize for ByteBufOwned {
         serializer.serialize_bytes(self.as_slice())
     }
 }
-
-impl<'de> serde::de::Deserialize<'de> for ByteBufOwned {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        struct Visitor;
-
-        impl<'de> serde::de::Visitor<'de> for Visitor {
-            type Value = ByteBufOwned;
-
-            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-                formatter.write_str("byte string")
-            }
-            fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
-            where
-                E: serde::de::Error,
-            {
-                Ok(ByteBufOwned::from(v.to_owned()))
-            }
-        }
-        Ok(deserializer.deserialize_byte_buf(Visitor {})?)
-    }
-}
-
-impl<'de: 'a, 'a> serde::de::Deserialize<'de> for ByteBuf<'a> {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        #[derive(Default)]
-        struct Visitor<'a> {
-            _p: PhantomData<&'a ()>,
-        }
-
-        impl<'de: 'a, 'a> serde::de::Visitor<'de> for Visitor<'a> {
-            type Value = ByteBuf<'a>;
-
-            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-                formatter.write_str("byte string")
-            }
-            fn visit_borrowed_bytes<E>(self, v: &'de [u8]) -> Result<Self::Value, E>
-            where
-                E: serde::de::Error,
-            {
-                Ok(ByteBuf::from(v))
-            }
-        }
-        Ok(deserializer.deserialize_byte_buf(Visitor::default())?)
-    }
-}
diff --git a/crates/librqbit/src/torrent_state/live/mod.rs b/crates/librqbit/src/torrent_state/live/mod.rs
index 532c3f0..c0a8ece 100644
--- a/crates/librqbit/src/torrent_state/live/mod.rs
+++ b/crates/librqbit/src/torrent_state/live/mod.rs
@@ -248,10 +248,10 @@ impl TorrentStateLive {
                         let stats = state.stats_snapshot();
                         let fetched = stats.fetched_bytes;
                         let needed = state.initially_needed();
-                        // TODO: this is very coarse, as it doesn't capture partially
-                        // downloaded pieces. But it's better than using "fetched" which is bugged,
-                        // see #92
-                        let remaining = needed - stats.downloaded_and_checked_bytes;
+                        // fetched can be too high in theory, so for safety make sure that it doesn't wrap around u64.
+                        let remaining = needed
+                            .wrapping_sub(fetched)
+                            .min(needed - stats.downloaded_and_checked_bytes);
                         state
                             .down_speed_estimator
                             .add_snapshot(fetched, Some(remaining), now);