1 files changed, 1 insertions, 0 deletions
diff --git a/dir.c b/dir.c
index e271503dce..ee3032d69f 100644
--- a/dir.c
+++ b/dir.c
@@ -1019,6 +1019,7 @@ check_dirname(VALUE dir)
     pend = rb_enc_path_end(rb_enc_path_skip_prefix(path, pend, enc), pend, enc);
     if (pend - path < len) {
 	d = rb_str_subseq(d, 0, pend - path);
+	StringValueCStr(d);
     }
     return rb_str_encode_ospath(d);
 }