diff --git a/intl/uconv/public/nsICharsetAlias.h b/intl/uconv/public/nsICharsetAlias.h
index 4588baa08ac..8767a81ca9a 100644
--- a/intl/uconv/public/nsICharsetAlias.h
+++ b/intl/uconv/public/nsICharsetAlias.h
@@ -53,9 +53,6 @@
 #define NS_CHARSETALIAS_CID \
 { 0x98d41c21, 0xccf3, 0x11d2, { 0xb3, 0xb1, 0x0, 0x80, 0x5f, 0x8a, 0x66, 0x70 }}
 
-#define NS_CHARSETALIAS_CID \
-{ 0x98d41c21, 0xccf3, 0x11d2, { 0xb3, 0xb1, 0x0, 0x80, 0x5f, 0x8a, 0x66, 0x70 }}
-
 #define NS_CHARSETALIAS_CONTRACTID "@mozilla.org/intl/charsetalias;1"
 
 class nsICharsetAlias : public nsISupports