diff --git a/mozilla/modules/libimg/src/xpcompat.cpp b/mozilla/modules/libimg/src/xpcompat.cpp
index 707eae04a46..30c752dc17f 100644
--- a/mozilla/modules/libimg/src/xpcompat.cpp
+++ b/mozilla/modules/libimg/src/xpcompat.cpp
@@ -31,6 +31,7 @@
 #include "plstr.h"
 #include "ilISystemServices.h"
 #include "nsCRT.h"
+#include "xp_mcom.h"
 
 extern ilISystemServices *il_ss;