diff --git a/ipc/glue/WindowsMessageLoop.cpp b/ipc/glue/WindowsMessageLoop.cpp
index e37f1b520678..a7aaca7edae4 100644
--- a/ipc/glue/WindowsMessageLoop.cpp
+++ b/ipc/glue/WindowsMessageLoop.cpp
@@ -396,6 +396,13 @@ WindowIsDeferredWindow(HWND hWnd)
     return true;
   }
 
+  // Google Earth bridging msg window between the plugin instance and a separate
+  // earth process. The earth process can trigger a plugin incall on the browser
+  // at any time, which is badness if the instance is already making an incall.
+  if (className.EqualsLiteral("__geplugin_bridge_window__")) {
+    return true;
+  }
+
   // nsNativeAppSupport makes a window like "FirefoxMessageWindow" based on the
   // toolkit app's name. It's pretty expensive to calculate this so we only try
   // once.