--- a/dom/media/webrtc/MediaEngine.h
+++ b/dom/media/webrtc/MediaEngine.h
@@ -221,27 +221,27 @@ public:
   class AllocationHandle
   {
   public:
     NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AllocationHandle);
   protected:
     ~AllocationHandle() {}
   public:
     AllocationHandle(const dom::MediaTrackConstraints& aConstraints,
-                     const ipc::PrincipalInfo& aPrincipalInfo,
+                     const mozilla::ipc::PrincipalInfo& aPrincipalInfo,
                      const MediaEnginePrefs& aPrefs,
                      const nsString& aDeviceId)
 
     : mConstraints(aConstraints),
       mPrincipalInfo(aPrincipalInfo),
       mPrefs(aPrefs),
       mDeviceId(aDeviceId) {}
   public:
     NormalizedConstraints mConstraints;
-    ipc::PrincipalInfo mPrincipalInfo;
+    mozilla::ipc::PrincipalInfo mPrincipalInfo;
     MediaEnginePrefs mPrefs;
     nsString mDeviceId;
   };
 
   /* Release the device back to the system. */
   virtual nsresult Deallocate(AllocationHandle* aHandle)
   {
     MOZ_ASSERT(aHandle);