1 files changed, 10 insertions, 4 deletions
diff --git a/src/string.c b/src/string.c
index fc5d43612..82f647db1 100644
--- a/src/string.c
+++ b/src/string.c
@@ -2537,11 +2537,17 @@ mrb_str_clear(mrb_state *mrb, mrb_value str)
 {
   struct RString *s = mrb_str_ptr(str);
 
-  if (!STR_SHARED_P(s) && !STR_EMBED_P(s) && ((s->flags & MRB_STR_NOFREE) == 0)) {
-    mrb_free(mrb, s->as.heap.ptr);
-    RSTRING(str)->as.heap.ptr = 0;
-    RSTRING(str)->as.heap.len = 0;
+  if (!STR_SHARED_P(s) && !STR_EMBED_P(s)) {
+    if (s->flags & MRB_STR_NOFREE) {
+      s->flags &= ~MRB_STR_NOFREE;
+    }
+    else {
+      mrb_free(mrb, s->as.heap.ptr);
+    }
+    s->as.heap.ptr = 0;
+    s->as.heap.len = 0;
   }
+  STR_UNSET_SHARED_FLAG(s);
   STR_SET_EMBED_FLAG(s);
   STR_SET_EMBED_LEN(s, 0);
   RSTRING_PTR(str)[0] = '\0';