--- a/hal/gonk/GonkSwitch.cpp
+++ b/hal/gonk/GonkSwitch.cpp
@@ -4,16 +4,17 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include <android/log.h>
 #include <sysutils/NetlinkEvent.h>
 
 #include "base/message_loop.h"
 
 #include "Hal.h"
+#include "mozilla/Monitor.h"
 #include "nsXULAppAPI.h"
 #include "UeventPoller.h"
 
 using namespace mozilla::hal;
 
 #define LOG(args...)  __android_log_print(ANDROID_LOG_INFO, "GonkSwitch" , ## args) 
 
 namespace mozilla {
@@ -149,28 +150,37 @@ ReleaseResourceIfNeed()
   if (sSwitchObserver->GetEnableCount() == 0) {
     UnregisterUeventListener(sSwitchObserver);
     delete sSwitchObserver;
     sSwitchObserver = NULL;
   }
 }
 
 static void
-EnableSwitchNotificationsIOThread(SwitchDevice aDevice)
+EnableSwitchNotificationsIOThread(SwitchDevice aDevice, Monitor *aMonitor)
 {
   InitializeResourceIfNeed();
   sSwitchObserver->EnableSwitch(aDevice);
+  {
+    MonitorAutoLock lock(*aMonitor);
+    lock.Notify();
+  }
 }
 
 void
 EnableSwitchNotifications(SwitchDevice aDevice)
 {
-  XRE_GetIOMessageLoop()->PostTask(
-      FROM_HERE,
-      NewRunnableFunction(EnableSwitchNotificationsIOThread, aDevice));
+  Monitor monitor("EnableSwitch.monitor");
+  {
+    MonitorAutoLock lock(monitor);
+    XRE_GetIOMessageLoop()->PostTask(
+        FROM_HERE,
+        NewRunnableFunction(EnableSwitchNotificationsIOThread, aDevice, &monitor));
+    lock.Wait();
+  }
 }
 
 static void
 DisableSwitchNotificationsIOThread(SwitchDevice aDevice)
 {
   MOZ_ASSERT(sSwitchObserver->GetEnableCount());
   sSwitchObserver->DisableSwitch(aDevice);
   ReleaseResourceIfNeed();