diff --git a/src/app/filestate.ts b/src/app/filestate.ts
index ebdc665..e121e5f 100644
--- a/src/app/filestate.ts
+++ b/src/app/filestate.ts
@@ -210,10 +210,13 @@ export class OpenFile implements WorkspaceFile {
     private changeSet: ChangeSet;
     get changes(): ChangeSet {
         if (!this.changeSet) {
-            this.changeSet = ChangeSet.empty(this.rootState.val.doc.length);
+            this.clearChanges();
         }
         return this.changeSet;
     }
+    clearChanges(): void {
+        this.changeSet = ChangeSet.empty(this.rootState.val.doc.length);
+    }
 
     // Return an EditorView to be used by the LSP Workspace for position mapping.
     // If `main` is provided and belongs to this open file, return it. Otherwise
diff --git a/src/app/lsp.ts b/src/app/lsp.ts
index 143a539..09d96bd 100644
--- a/src/app/lsp.ts
+++ b/src/app/lsp.ts
@@ -109,7 +109,7 @@ class OpenFileWorkspace extends Workspace {
                 result.push({ file, prevDoc, changes });
                 file.doc = file.rootState.val.doc;
                 file.version = this.nextFileVersion(file.uri);
-                file.changes = ChangeSet.empty(file.doc.length);
+                file.clearChanges();
             }
             for (const e of file.editors) {
                 const plugin = LSPPlugin.get(e.view);