diff --git a/libiberty/getopt.c b/libiberty/getopt.c
index 2f7086cc0c89..48736d4db418 100644
--- a/libiberty/getopt.c
+++ b/libiberty/getopt.c
@@ -23,12 +23,6 @@
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
    USA.  */
 
-/* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>.
-   Ditto for AIX 3.2 and <stdlib.h>.  */
-#ifndef _NO_PROTO
-# define _NO_PROTO
-#endif
-
 #ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif