diff --git a/vlib/io/util/util.v b/vlib/io/util/util.v
index 5db3e7d7c3..0d899ed1d6 100644
--- a/vlib/io/util/util.v
+++ b/vlib/io/util/util.v
@@ -77,18 +77,9 @@ fn random_number() string {
 }
 
 fn prefix_and_suffix(pattern string) !(string, string) {
-	mut pat := pattern
-	if pat.contains(os.path_separator) {
+	if pattern.contains(os.path_separator) {
 		return error('pattern cannot contain path separators (${os.path_separator}).')
 	}
-	pos := pat.index_u8_last(`*`)
-	mut prefix := ''
-	mut suffix := ''
-	if pos != -1 {
-		prefix = pat.substr(0, pos)
-		suffix = pat.substr(pos + 1, pat.len)
-	} else {
-		prefix = pat
-	}
+	prefix, suffix := pattern.rsplit_once('*') or { pattern, '' }
 	return prefix, suffix
 }