diff --git a/mozilla/xpcom/base/IIDS.h b/mozilla/xpcom/base/IIDS.h
index f0fd21d7bd5..b1d1a6fc5c4 100644
--- a/mozilla/xpcom/base/IIDS.h
+++ b/mozilla/xpcom/base/IIDS.h
@@ -719,7 +719,7 @@ nsIDOMEvent = { /* a6cf90c3-15b3-11d2-932e-00805f8add32 */
     0x11d2,
     {0x93, 0x2e, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32}
   };
-nsIDOMNSEvent = { /* a6cf90c4-15b3-11d2-932e-00805f8add32 */
+nsIDOMNSUIEvent = { /* a6cf90c4-15b3-11d2-932e-00805f8add32 */
     0xa6cf90c4,
     0x15b3,
     0x11d2,