1 files changed, 1 insertions, 1 deletions

diff --git a/networking/httpd_indexcgi.c b/networking/httpd_indexcgi.c
index 2605ad1bc..6663a22ad 100644
--- a/networking/httpd_indexcgi.c
+++ b/networking/httpd_indexcgi.c
@@ -149,7 +149,7 @@ static void fmt_url(/*char *dst,*/ const char *name)
                 guarantee(3);
                 *dst = c;
                 if ((c - '0') > 9 /* not a digit */
-                 && ((c|0x20) - 'a') > 26 /* not A-Z or a-z */
+                 && ((c|0x20) - 'a') > ('z' - 'a') /* not A-Z or a-z */
                  && !strchr("._-+@", c)
                 ) {
                         *dst++ = '%';