diff --git a/packages/plugin-undo-redo/src/index.tsx b/packages/plugin-undo-redo/src/index.tsx
index 8357bf4e2..42d31de1d 100644
--- a/packages/plugin-undo-redo/src/index.tsx
+++ b/packages/plugin-undo-redo/src/index.tsx
@@ -68,11 +68,11 @@ export default class UndoRedo extends PureComponent<IProps, IState> {
   };
 
   handleUndoClick = (): void => {
-    this.history?.back();
+    this.history.back();
   };
 
   handleRedoClick = (): void => {
-    this.history?.forward();
+    this.history.forward();
   };
 
   render(): React.ReactNode {