diff --git a/uriloader/exthandler/mac/nsInternetConfig.h b/uriloader/exthandler/mac/nsInternetConfig.h
index 43c2eb7d9dd..90121624d3e 100644
--- a/uriloader/exthandler/mac/nsInternetConfig.h
+++ b/uriloader/exthandler/mac/nsInternetConfig.h
@@ -19,6 +19,10 @@
  *
  * Contributor(s): 
  */
+ 
+#ifndef __NS_INTERNETCONFIG_H__
+#define __NS_INTERNETCONFIG_H__
+
 #include <InternetConfig.h>
 #include "PRTypes.h"
 #include "nsError.h"
@@ -36,4 +40,6 @@ private:
 	static	ICInstance sInstance;
 	static  long sSeed;
 	static  PRInt32 sRefCount;
-};
\ No newline at end of file
+};
+
+#endif /* __NS_INTERNETCONFIG_H__ */
diff --git a/xpfe/appshell/src/nsInternetConfig.h b/xpfe/appshell/src/nsInternetConfig.h
index 43c2eb7d9dd..90121624d3e 100644
--- a/xpfe/appshell/src/nsInternetConfig.h
+++ b/xpfe/appshell/src/nsInternetConfig.h
@@ -19,6 +19,10 @@
  *
  * Contributor(s): 
  */
+ 
+#ifndef __NS_INTERNETCONFIG_H__
+#define __NS_INTERNETCONFIG_H__
+
 #include <InternetConfig.h>
 #include "PRTypes.h"
 #include "nsError.h"
@@ -36,4 +40,6 @@ private:
 	static	ICInstance sInstance;
 	static  long sSeed;
 	static  PRInt32 sRefCount;
-};
\ No newline at end of file
+};
+
+#endif /* __NS_INTERNETCONFIG_H__ */