diff --git a/crates/language/src/syntax_map.rs b/crates/language/src/syntax_map.rs
index bd24424679f3e6cb02303c91e0d86db335cd0a26..c5931c474d2962fc7ceb66954f2f00d3bf14b4f8 100644
--- a/crates/language/src/syntax_map.rs
+++ b/crates/language/src/syntax_map.rs
@@ -13,7 +13,7 @@ use std::{
     collections::BinaryHeap,
     fmt, iter,
     ops::{ControlFlow, Deref, DerefMut, Range},
-    sync::Arc,
+    sync::{Arc, LazyLock},
     time::{Duration, Instant},
 };
 use streaming_iterator::StreamingIterator;
@@ -40,6 +40,27 @@ pub struct SyntaxSnapshot {
     update_count: usize,
 }
 
+// Dropping deep treesitter Trees can be quite slow due to deallocating lots of memory.
+// To avoid blocking the main thread, we offload the drop operation to a background thread.
+impl Drop for SyntaxSnapshot {
+    fn drop(&mut self) {
+        static DROP_TX: LazyLock<std::sync::mpsc::Sender<SumTree<SyntaxLayerEntry>>> =
+            LazyLock::new(|| {
+                let (tx, rx) = std::sync::mpsc::channel();
+                std::thread::Builder::new()
+                    .name("SyntaxSnapshot::drop".into())
+                    .spawn(move || while let Ok(_) = rx.recv() {})
+                    .expect("failed to spawn drop thread");
+                tx
+            });
+        // This does allocate a new Arc, but it's cheap and avoids blocking the main thread without needing to use an `Option` or `MaybeUninit`.
+        let _ = DROP_TX.send(std::mem::replace(
+            &mut self.layers,
+            SumTree::from_summary(Default::default()),
+        ));
+    }
+}
+
 #[derive(Default)]
 pub struct SyntaxMapCaptures<'a> {
     layers: Vec<SyntaxMapCapturesLayer<'a>>,