diff --git a/vscode/src/tree-sitter/parse-tree-cache.ts b/vscode/src/tree-sitter/parse-tree-cache.ts
index 98209893efd9..1bccffcf93e1 100644
--- a/vscode/src/tree-sitter/parse-tree-cache.ts
+++ b/vscode/src/tree-sitter/parse-tree-cache.ts
@@ -8,6 +8,9 @@ import { type WrappedParser, createParser, getParser } from './parser'
 
 const parseTreesPerFile = new LRUCache<string, Tree>({
     max: 10,
+    // Important: we need to call `Tree.delete()` to free up memory. Without
+    // this, we leak memory. See CODY-3616.
+    disposeAfter: tree => tree.delete(),
 })
 
 interface ParseTreeCache {