diff --git a/packages/frontend-app-api/src/wiring/graph/types.ts b/packages/frontend-app-api/src/wiring/graph/types.ts
index b828c9762e..6e205db9dd 100644
--- a/packages/frontend-app-api/src/wiring/graph/types.ts
+++ b/packages/frontend-app-api/src/wiring/graph/types.ts
@@ -48,7 +48,7 @@ export interface AppNodeEdges {
  */
 export interface AppNodeInstance {
   getDataRefs(): Iterable<ExtensionDataRef<unknown>>;
-  getData<T>(ref: ExtensionDataRef<T>): T | unknown;
+  getData<T>(ref: ExtensionDataRef<T>): T | undefined;
 }
 
 /**