--- nethack-3.4.0/src/mkmaze.c.redhat	Fri Mar 22 14:51:19 2002
+++ nethack-3.4.0/src/mkmaze.c	Fri Mar 22 15:30:43 2002
@@ -521,7 +521,7 @@
 	    char *ep = getenv("SPLEVTYPE");	/* not nh_getenv */
 	    if (ep) {
 		/* rindex always succeeds due to code in prior block */
-		int len = (rindex(protofile, '-') - protofile) + 1;
+		int len = ((char *)rindex(protofile, '-') - protofile) + 1;
 
 		while (ep && *ep) {
 		    if (!strncmp(ep, protofile, len)) {