diff --git a/crates/channel/src/channel_chat.rs b/crates/channel/src/channel_chat.rs
index 1a9e46db0460a9..e5b5b74c16262b 100644
--- a/crates/channel/src/channel_chat.rs
+++ b/crates/channel/src/channel_chat.rs
@@ -808,7 +808,7 @@ pub fn mentions_to_proto(mentions: &[(Range<usize>, UserId)]) -> Vec<proto::Chat
 impl sum_tree::Item for ChannelMessage {
     type Summary = ChannelMessageSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         ChannelMessageSummary {
             max_id: self.id,
             count: 1,
diff --git a/crates/editor/src/display_map/block_map.rs b/crates/editor/src/display_map/block_map.rs
index efa026a56c6101..52e0ca2486d25d 100644
--- a/crates/editor/src/display_map/block_map.rs
+++ b/crates/editor/src/display_map/block_map.rs
@@ -1360,7 +1360,7 @@ impl<'a> Iterator for BlockBufferRows<'a> {
 impl sum_tree::Item for Transform {
     type Summary = TransformSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.summary.clone()
     }
 }
diff --git a/crates/editor/src/display_map/crease_map.rs b/crates/editor/src/display_map/crease_map.rs
index c3f2b0061ac732..531c650c43a6ed 100644
--- a/crates/editor/src/display_map/crease_map.rs
+++ b/crates/editor/src/display_map/crease_map.rs
@@ -291,7 +291,7 @@ impl sum_tree::Summary for ItemSummary {
 impl sum_tree::Item for CreaseItem {
     type Summary = ItemSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &MultiBufferSnapshot) -> Self::Summary {
         ItemSummary {
             range: self.crease.range.clone(),
         }
diff --git a/crates/editor/src/display_map/fold_map.rs b/crates/editor/src/display_map/fold_map.rs
index 37983030b8e1a7..5eb26ff9693883 100644
--- a/crates/editor/src/display_map/fold_map.rs
+++ b/crates/editor/src/display_map/fold_map.rs
@@ -944,7 +944,7 @@ struct TransformSummary {
 impl sum_tree::Item for Transform {
     type Summary = TransformSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.summary.clone()
     }
 }
@@ -1004,7 +1004,7 @@ impl Default for FoldRange {
 impl sum_tree::Item for Fold {
     type Summary = FoldSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &MultiBufferSnapshot) -> Self::Summary {
         FoldSummary {
             start: self.range.start,
             end: self.range.end,
diff --git a/crates/editor/src/display_map/inlay_map.rs b/crates/editor/src/display_map/inlay_map.rs
index 712db45e3f61a7..d4e39f2df9270e 100644
--- a/crates/editor/src/display_map/inlay_map.rs
+++ b/crates/editor/src/display_map/inlay_map.rs
@@ -74,7 +74,7 @@ impl Inlay {
 impl sum_tree::Item for Transform {
     type Summary = TransformSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         match self {
             Transform::Isomorphic(summary) => TransformSummary {
                 input: summary.clone(),
diff --git a/crates/editor/src/display_map/wrap_map.rs b/crates/editor/src/display_map/wrap_map.rs
index 564bba2158030e..dc4d93058cdf7f 100644
--- a/crates/editor/src/display_map/wrap_map.rs
+++ b/crates/editor/src/display_map/wrap_map.rs
@@ -917,7 +917,7 @@ impl Transform {
 impl sum_tree::Item for Transform {
     type Summary = TransformSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.summary.clone()
     }
 }
diff --git a/crates/editor/src/git/blame.rs b/crates/editor/src/git/blame.rs
index 733d42d0c57dda..303ead16b22319 100644
--- a/crates/editor/src/git/blame.rs
+++ b/crates/editor/src/git/blame.rs
@@ -29,7 +29,7 @@ pub struct GitBlameEntrySummary {
 impl sum_tree::Item for GitBlameEntry {
     type Summary = GitBlameEntrySummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         GitBlameEntrySummary { rows: self.rows }
     }
 }
diff --git a/crates/git/src/diff.rs b/crates/git/src/diff.rs
index 1f7930ce1442da..baad824577d301 100644
--- a/crates/git/src/diff.rs
+++ b/crates/git/src/diff.rs
@@ -34,7 +34,7 @@ struct InternalDiffHunk {
 impl sum_tree::Item for InternalDiffHunk {
     type Summary = DiffHunkSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &text::BufferSnapshot) -> Self::Summary {
         DiffHunkSummary {
             buffer_range: self.buffer_range.clone(),
         }
diff --git a/crates/gpui/src/elements/list.rs b/crates/gpui/src/elements/list.rs
index d03392867b5ee2..6ac6d2a9bf8d7d 100644
--- a/crates/gpui/src/elements/list.rs
+++ b/crates/gpui/src/elements/list.rs
@@ -858,7 +858,7 @@ impl Styled for List {
 impl sum_tree::Item for ListItem {
     type Summary = ListItemSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _: &()) -> Self::Summary {
         match self {
             ListItem::Unmeasured { focus_handle } => ListItemSummary {
                 count: 1,
diff --git a/crates/language/src/diagnostic_set.rs b/crates/language/src/diagnostic_set.rs
index c35659d9bbd4d1..38d4216beeabc4 100644
--- a/crates/language/src/diagnostic_set.rs
+++ b/crates/language/src/diagnostic_set.rs
@@ -224,7 +224,7 @@ impl DiagnosticSet {
 impl sum_tree::Item for DiagnosticEntry<Anchor> {
     type Summary = Summary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &text::BufferSnapshot) -> Self::Summary {
         Summary {
             start: self.range.start,
             end: self.range.end,
diff --git a/crates/language/src/syntax_map.rs b/crates/language/src/syntax_map.rs
index 55177f79620db7..8617696cc471ec 100644
--- a/crates/language/src/syntax_map.rs
+++ b/crates/language/src/syntax_map.rs
@@ -1739,7 +1739,7 @@ impl<'a> SeekTarget<'a, SyntaxLayerSummary, SyntaxLayerSummary>
 impl sum_tree::Item for SyntaxLayerEntry {
     type Summary = SyntaxLayerSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &BufferSnapshot) -> Self::Summary {
         SyntaxLayerSummary {
             min_depth: self.depth,
             max_depth: self.depth,
diff --git a/crates/multi_buffer/src/multi_buffer.rs b/crates/multi_buffer/src/multi_buffer.rs
index 828b39967d9e1f..7aa733ba8fa373 100644
--- a/crates/multi_buffer/src/multi_buffer.rs
+++ b/crates/multi_buffer/src/multi_buffer.rs
@@ -4596,7 +4596,7 @@ impl fmt::Debug for Excerpt {
 impl sum_tree::Item for Excerpt {
     type Summary = ExcerptSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         let mut text = self.text_summary.clone();
         if self.has_trailing_newline {
             text += TextSummary::from("\n");
@@ -4613,7 +4613,7 @@ impl sum_tree::Item for Excerpt {
 impl sum_tree::Item for ExcerptIdMapping {
     type Summary = ExcerptId;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.id
     }
 }
diff --git a/crates/notifications/src/notification_store.rs b/crates/notifications/src/notification_store.rs
index 48fcb5dfbb830a..5c3de53ee1895c 100644
--- a/crates/notifications/src/notification_store.rs
+++ b/crates/notifications/src/notification_store.rs
@@ -455,7 +455,7 @@ impl EventEmitter<NotificationEvent> for NotificationStore {}
 impl sum_tree::Item for NotificationEntry {
     type Summary = NotificationSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         NotificationSummary {
             max_id: self.id,
             count: 1,
diff --git a/crates/rope/src/rope.rs b/crates/rope/src/rope.rs
index 56fe7fc0544471..68ff7d5c6956aa 100644
--- a/crates/rope/src/rope.rs
+++ b/crates/rope/src/rope.rs
@@ -1159,7 +1159,7 @@ impl Chunk {
 impl sum_tree::Item for Chunk {
     type Summary = ChunkSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         ChunkSummary::from(self.0.as_str())
     }
 }
diff --git a/crates/sum_tree/src/sum_tree.rs b/crates/sum_tree/src/sum_tree.rs
index 7013dc66fd1ed7..fbfe3b06f3ab4c 100644
--- a/crates/sum_tree/src/sum_tree.rs
+++ b/crates/sum_tree/src/sum_tree.rs
@@ -20,7 +20,7 @@ pub const TREE_BASE: usize = 6;
 pub trait Item: Clone {
     type Summary: Summary;
 
-    fn summary(&self) -> Self::Summary;
+    fn summary(&self, cx: &<Self::Summary as Summary>::Context) -> Self::Summary;
 }
 
 /// An [`Item`] whose summary has a specific key that can be used to identify it
@@ -211,7 +211,7 @@ impl<T: Item> SumTree<T> {
         while iter.peek().is_some() {
             let items: ArrayVec<T, { 2 * TREE_BASE }> = iter.by_ref().take(2 * TREE_BASE).collect();
             let item_summaries: ArrayVec<T::Summary, { 2 * TREE_BASE }> =
-                items.iter().map(|item| item.summary()).collect();
+                items.iter().map(|item| item.summary(cx)).collect();
 
             let mut summary = item_summaries[0].clone();
             for item_summary in &item_summaries[1..] {
@@ -281,7 +281,7 @@ impl<T: Item> SumTree<T> {
             .map(|items| {
                 let items: ArrayVec<T, { 2 * TREE_BASE }> = items.into_iter().collect();
                 let item_summaries: ArrayVec<T::Summary, { 2 * TREE_BASE }> =
-                    items.iter().map(|item| item.summary()).collect();
+                    items.iter().map(|item| item.summary(cx)).collect();
                 let mut summary = item_summaries[0].clone();
                 for item_summary in &item_summaries[1..] {
                     <T::Summary as Summary>::add_summary(&mut summary, item_summary, cx);
@@ -405,7 +405,7 @@ impl<T: Item> SumTree<T> {
                 if let Some((item, item_summary)) = items.last_mut().zip(item_summaries.last_mut())
                 {
                     (f)(item);
-                    *item_summary = item.summary();
+                    *item_summary = item.summary(cx);
                     *summary = sum(item_summaries.iter(), cx);
                     Some(summary.clone())
                 } else {
@@ -461,7 +461,7 @@ impl<T: Item> SumTree<T> {
     }
 
     pub fn push(&mut self, item: T, cx: &<T::Summary as Summary>::Context) {
-        let summary = item.summary();
+        let summary = item.summary(cx);
         self.append(
             SumTree(Arc::new(Node::Leaf {
                 summary: summary.clone(),
@@ -1352,7 +1352,7 @@ mod tests {
     impl Item for u8 {
         type Summary = IntegersSummary;
 
-        fn summary(&self) -> Self::Summary {
+        fn summary(&self, _cx: &()) -> Self::Summary {
             IntegersSummary {
                 count: 1,
                 sum: *self as usize,
diff --git a/crates/sum_tree/src/tree_map.rs b/crates/sum_tree/src/tree_map.rs
index c57226b681432a..9a4d952e93f226 100644
--- a/crates/sum_tree/src/tree_map.rs
+++ b/crates/sum_tree/src/tree_map.rs
@@ -224,7 +224,7 @@ where
 {
     type Summary = MapKey<K>;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.key()
     }
 }
diff --git a/crates/text/src/locator.rs b/crates/text/src/locator.rs
index 7afc16f5815496..e38b9b58af22c2 100644
--- a/crates/text/src/locator.rs
+++ b/crates/text/src/locator.rs
@@ -69,7 +69,7 @@ impl Default for Locator {
 impl sum_tree::Item for Locator {
     type Summary = Locator;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.clone()
     }
 }
diff --git a/crates/text/src/operation_queue.rs b/crates/text/src/operation_queue.rs
index c7964f62674ca5..52b534a41b7395 100644
--- a/crates/text/src/operation_queue.rs
+++ b/crates/text/src/operation_queue.rs
@@ -107,7 +107,7 @@ impl<'a> Dimension<'a, OperationSummary> for OperationKey {
 impl<T: Operation> Item for OperationItem<T> {
     type Summary = OperationSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         OperationSummary {
             key: OperationKey::new(self.0.lamport_timestamp()),
             len: 1,
diff --git a/crates/text/src/text.rs b/crates/text/src/text.rs
index 8bdc9fdb03d89b..80eafcf4eba2d5 100644
--- a/crates/text/src/text.rs
+++ b/crates/text/src/text.rs
@@ -2617,7 +2617,7 @@ impl Fragment {
 impl sum_tree::Item for Fragment {
     type Summary = FragmentSummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &Option<clock::Global>) -> Self::Summary {
         let mut max_version = clock::Global::new();
         max_version.observe(self.timestamp);
         for deletion in &self.deletions {
@@ -2688,7 +2688,7 @@ impl Default for FragmentSummary {
 impl sum_tree::Item for InsertionFragment {
     type Summary = InsertionFragmentKey;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         InsertionFragmentKey {
             timestamp: self.timestamp,
             split_offset: self.split_offset,
@@ -2700,7 +2700,7 @@ impl sum_tree::KeyedItem for InsertionFragment {
     type Key = InsertionFragmentKey;
 
     fn key(&self) -> Self::Key {
-        sum_tree::Item::summary(self)
+        sum_tree::Item::summary(self, &())
     }
 }
 
diff --git a/crates/text/src/undo_map.rs b/crates/text/src/undo_map.rs
index 4e670fd456068d..ed363cfc6b6d77 100644
--- a/crates/text/src/undo_map.rs
+++ b/crates/text/src/undo_map.rs
@@ -11,7 +11,7 @@ struct UndoMapEntry {
 impl sum_tree::Item for UndoMapEntry {
     type Summary = UndoMapKey;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         self.key
     }
 }
diff --git a/crates/worktree/src/worktree.rs b/crates/worktree/src/worktree.rs
index d81c91132b9d39..a3daf8ea2eade7 100644
--- a/crates/worktree/src/worktree.rs
+++ b/crates/worktree/src/worktree.rs
@@ -3339,7 +3339,7 @@ impl EntryKind {
 impl sum_tree::Item for Entry {
     type Summary = EntrySummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         let non_ignored_count = if self.is_ignored || self.is_external {
             0
         } else {
@@ -3434,7 +3434,7 @@ struct PathEntry {
 impl sum_tree::Item for PathEntry {
     type Summary = PathEntrySummary;
 
-    fn summary(&self) -> Self::Summary {
+    fn summary(&self, _cx: &()) -> Self::Summary {
         PathEntrySummary { max_id: self.id }
     }
 }