diff --git a/lib/libc/regex/regerror.c b/lib/libc/regex/regerror.c
index 1ed6771ffec..b1d151d40c8 100644
--- a/lib/libc/regex/regerror.c
+++ b/lib/libc/regex/regerror.c
@@ -44,7 +44,6 @@ static char sccsid[] = "@(#)regerror.c	8.4 (Berkeley) 3/20/94";
 #include <sys/types.h>
 #include <stdio.h>
 #include <string.h>
-#include <ctype.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <regex.h>