diff --git a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
index 09438e541753f536f84c7d941d61d3d26aa1d550..a58e626db11a1c6b060e22251f2d26b9be815f9c 100644
--- a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
+++ b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
@@ -100,7 +100,7 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 		editor: ICodeEditor,
 		private _owner: string,
 		private _commentThread: modes.CommentThread,
-		private _pendingComment: string,
+		private _pendingComment: string | null,
 		@IInstantiationService private instantiationService: IInstantiationService,
 		@IModeService private modeService: IModeService,
 		@IModelService private modelService: IModelService,