1 files changed, 1 insertions, 0 deletions
diff --git a/string.c b/string.c
index 9a9de2e64b..3f348f2662 100644
--- a/string.c
+++ b/string.c
@@ -1569,6 +1569,7 @@ rb_str_rindex(VALUE str, VALUE sub, long pos)
     sbeg = RSTRING_PTR(str);
     e = RSTRING_END(str);
     t = RSTRING_PTR(sub);
+    slen = RSTRING_LEN(sub);
     for (;;) {
 	s = str_nth(sbeg, e, pos, enc, asc);
 	if (!s) return -1;