diff --git a/ipc/glue/WindowsMessageLoop.cpp b/ipc/glue/WindowsMessageLoop.cpp
index adbda8e820e2..0a30210239ec 100644
--- a/ipc/glue/WindowsMessageLoop.cpp
+++ b/ipc/glue/WindowsMessageLoop.cpp
@@ -240,12 +240,6 @@ ProcessOrDeferMessage(HWND hwnd,
       deferred = new DeferredRedrawMessage(hwnd, flags);
       break;
     }
-    case WM_NCPAINT: {
-      UINT flags = RDW_INVALIDATE | RDW_FRAME | RDW_NOINTERNALPAINT |
-                   RDW_NOERASE | RDW_NOCHILDREN | RDW_ERASENOW;
-      deferred = new DeferredRedrawMessage(hwnd, flags);
-      break;
-    }
 
     // This message will generate a WM_PAINT message if there are invalid
     // areas.
@@ -289,6 +283,7 @@ ProcessOrDeferMessage(HWND hwnd,
     // Messages that are safe to pass to DefWindowProc go here.
     case WM_ENTERIDLE:
     case WM_GETICON:
+    case WM_NCPAINT: // (never trap nc paint events)
     case WM_GETMINMAXINFO:
     case WM_GETTEXT:
     case WM_NCHITTEST: