diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index beafd1b90..528e753f1 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2007-01-17  Corinna Vinschen  <corinna@vinschen.de>
+
+	* include/asm/socket.h (SIOGIFINDEX): Define.
+
 2007-01-17  Corinna Vinschen  <corinna@vinschen.de>
 
 	* mmap.cc (MapView9x): Note possible uselessness of retrying.
diff --git a/winsup/cygwin/include/asm/socket.h b/winsup/cygwin/include/asm/socket.h
index 637cec294..4541bc850 100644
--- a/winsup/cygwin/include/asm/socket.h
+++ b/winsup/cygwin/include/asm/socket.h
@@ -42,6 +42,7 @@ details. */
 #define SIOCGIFMETRIC   _IOW('s', 106, struct ifreq) /* get metric */
 #define SIOCGIFMTU      _IOW('s', 107, struct ifreq) /* get MTU size */
 #define SIOCGIFINDEX    _IOW('s', 108, struct ifreq) /* get if index */
+#define SIOGIFINDEX SIOCGIFINDEX /* backward compatibility w/ Linux typo. */
 
 #define SOL_SOCKET      0xffff          /* options for socket level */