--- a/widget/windows/nsAppShell.cpp
+++ b/widget/windows/nsAppShell.cpp
@@ -535,16 +535,17 @@ nsAppShell::ProcessNextNativeEvent(bool 
 
         ::TranslateMessage(&msg);
         ::DispatchMessageW(&msg);
       }
     } else if (mayWait) {
       // Block and wait for any posted application message
       mozilla::HangMonitor::Suspend();
       {
+        AUTO_PROFILER_LABEL("nsAppShell::ProcessNextNativeEvent::Wait", IDLE);
         AUTO_PROFILER_THREAD_SLEEP;
         WinUtils::WaitForMessage();
       }
     }
   } while (!gotMessage && mayWait);
 
   // See DoProcessNextNativeEvent, mEventloopNestingLevel will be
   // one when a modal loop unwinds.