diff --git a/embed/mozilla/MozRegisterComponents.cpp b/embed/mozilla/MozRegisterComponents.cpp
index 81cd2fa..dfdef4e 100644
--- a/embed/mozilla/MozRegisterComponents.cpp
+++ b/embed/mozilla/MozRegisterComponents.cpp
@@ -46,6 +46,7 @@
 #include <nsIClassInfoImpl.h>
 #include <nsXULAppAPI.h>
 #include <nsToolkitCompsCID.h>
+#include <nsXPCOMCIDInternal.h>
 #endif
 
 #ifdef HAVE_MOZILLA_PSM