diff --git a/libs/port/getopt.c b/libs/port/getopt.c
index dae56ec5c49..7bcf2795e6a 100644
--- a/libs/port/getopt.c
+++ b/libs/port/getopt.c
@@ -212,7 +212,7 @@ static char *posixly_correct;
 # define my_index	strchr
 #else
 
-# if HAVE_STRING_H
+# ifdef HAVE_STRING_H
 #  include <string.h>
 # else
 #  include <strings.h>