diff --git a/src/renderer/components/test-utils/get-application-builder.tsx b/src/renderer/components/test-utils/get-application-builder.tsx
index 616d29f13d..42401e1288 100644
--- a/src/renderer/components/test-utils/get-application-builder.tsx
+++ b/src/renderer/components/test-utils/get-application-builder.tsx
@@ -556,7 +556,7 @@ const disableExtensionsFor = <T extends ObservableSet>(
       runInAction(() => {
         extension.deregister();
 
-        extensionState.delete(extension);
+        extensionState.delete(instance);
       });
     });
   };