--- a/toolkit/components/filewatcher/NativeFileWatcherWin.cpp
+++ b/toolkit/components/filewatcher/NativeFileWatcherWin.cpp
@@ -1334,17 +1334,17 @@ NativeFileWatcherService::AddPath(const 
         &NativeFileWatcherIOTask::AddPathRunnableMethod,
         wrappedCallbacks.get()),
       nsIEventTarget::DISPATCH_NORMAL);
   if (NS_FAILED(rv)) {
     return rv;
   }
 
   // Since the dispatch succeeded, we let the runnable own the pointer.
-  wrappedCallbacks.release();
+  Unused << wrappedCallbacks.release();
 
   WakeUpWorkerThread();
 
   return NS_OK;
 }
 
 /**
  * Removes the path from the list of watched resources. Silently ignores the request
@@ -1408,17 +1408,17 @@ NativeFileWatcherService::RemovePath(con
         &NativeFileWatcherIOTask::RemovePathRunnableMethod,
         wrappedCallbacks.get()),
       nsIEventTarget::DISPATCH_NORMAL);
   if (NS_FAILED(rv)) {
     return rv;
   }
 
   // Since the dispatch succeeded, we let the runnable own the pointer.
-  wrappedCallbacks.release();
+  Unused << wrappedCallbacks.release();
 
   WakeUpWorkerThread();
 
   return NS_OK;
 }
 
 /**
  * Removes all the watched resources from the watch list and stops the