1 files changed, 1 insertions, 1 deletions
diff --git a/string.c b/string.c
index c27e5d486..2017d1023 100644
--- a/string.c
+++ b/string.c
@@ -4681,7 +4681,7 @@ tr_trans(VALUE str, VALUE src, VALUE repl, int sflag)
 	    if (r == errc) r = trrepl.now;
 	    if (c < 256) {
 		trans[c] = r;
-		if (r > 255) singlebyte = 0;
+		if (rb_enc_codelen(r, enc) != 1) singlebyte = 0;
 	    }
 	    else {
 		if (!hash) hash = rb_hash_new();