ngx_strcasecmp()/ngx_strncasecmp()
diff --git a/src/core/ngx_inet.c b/src/core/ngx_inet.c
index 09ff014..de4cae2 100644
--- a/src/core/ngx_inet.c
+++ b/src/core/ngx_inet.c
@@ -233,7 +233,7 @@
     len = u->url.len;
     p = u->url.data;
 
-    if (ngx_strncasecmp(p, "unix:", 5) == 0) {
+    if (ngx_strncasecmp(p, (u_char *) "unix:", 5) == 0) {
 
 #if (NGX_HAVE_UNIX_DOMAIN)