--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -8941,17 +8941,17 @@ public:
     return result.forget();
   }
 
   void
   NoteFinishedMaintenance(Maintenance* aMaintenance)
   {
     AssertIsOnBackgroundThread();
     MOZ_ASSERT(aMaintenance);
-    MOZ_ASSERT(mCurrentMaintenance = aMaintenance);
+    MOZ_ASSERT(mCurrentMaintenance == aMaintenance);
 
     mCurrentMaintenance = nullptr;
     ProcessMaintenanceQueue();
   }
 
   nsThreadPool*
   GetOrCreateThreadPool();