diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 8c953e85c..3878cfeb5 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2013-01-21  Christopher Faylor  <me.cygwin2013@cgf.cx>
+
+	* cygerrno.h: Conditionally define __regN for cygserver.
+
 2013-01-20  Christopher Faylor  <me.cygwin2013@cgf.cx>
 
 	* malloc_wrapper.cc (malloc_init): Re-add inadvertently dropped comment
diff --git a/winsup/cygwin/cygerrno.h b/winsup/cygwin/cygerrno.h
index c861907b6..677b3b0af 100644
--- a/winsup/cygwin/cygerrno.h
+++ b/winsup/cygwin/cygerrno.h
@@ -13,6 +13,16 @@ details. */
 #define _CYGERRNO_H
 #include <errno.h>
 
+#ifndef __reg1
+# define __reg1 __stdcall __attribute__ ((regparm (1)))
+#endif
+#ifndef __reg2
+# define __reg2 __stdcall __attribute__ ((regparm (2)))
+#endif
+#ifndef __reg2
+# define __reg2 __stdcall __attribute__ ((regparm (2)))
+#endif
+
 void __reg3 seterrno_from_win_error (const char *file, int line, DWORD code);
 void __reg3 seterrno_from_nt_status (const char *file, int line, NTSTATUS status);
 void __reg2 seterrno (const char *, int line);