diff --git a/git-compat-util.h b/git-compat-util.h
index 9f941e42b1..71b5acb6fa 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -57,10 +57,8 @@
 # endif
 #elif !defined(__APPLE__) && !defined(__FreeBSD__)  && !defined(__USLC__) && !defined(_M_UNIX) && !defined(sgi)
 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
-#ifndef __sun__
 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 #endif
-#endif
 #define _ALL_SOURCE 1
 #define _GNU_SOURCE 1
 #define _BSD_SOURCE 1