diff --git a/web/app/components/workflow/nodes/_base/components/add-variable-popup-with-position.tsx b/web/app/components/workflow/nodes/_base/components/add-variable-popup-with-position.tsx
index 657b910ee9..d0f971f849 100644
--- a/web/app/components/workflow/nodes/_base/components/add-variable-popup-with-position.tsx
+++ b/web/app/components/workflow/nodes/_base/components/add-variable-popup-with-position.tsx
@@ -29,7 +29,7 @@ const AddVariablePopupWithPosition = ({
   nodeId,
   nodeData,
 }: AddVariablePopupWithPositionProps) => {
-  const ref = useRef(null)
+  const ref = useRef<HTMLDivElement>(null)
   const showAssignVariablePopup = useStore(s => s.showAssignVariablePopup)
   const setShowAssignVariablePopup = useStore(s => s.setShowAssignVariablePopup)
   const { handleNodeDataUpdate } = useNodeDataUpdate()