diff --git a/usr.bin/mkcsmapper/yacc.y b/usr.bin/mkcsmapper/yacc.y
index 97aade1ff5b..89ce5fd6989 100644
--- a/usr.bin/mkcsmapper/yacc.y
+++ b/usr.bin/mkcsmapper/yacc.y
@@ -664,7 +664,7 @@ do_mkpv(FILE *in)
 	if (ret && output)
 		unlink(output); /* dump failure */
 	if (ret)
-		errc(EXIT_FAILURE, ret, "");
+		errx(EXIT_FAILURE, "%s\n", strerror(ret));
 }
 
 static void