2 files changed, 12 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 2ff34a0ca2..e0d0ba990f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Apr  1 08:58:39 2014  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* parse.y (rb_str_dynamic_intern): set mark bit if dynamic symbol
+	  is before sweeping.
+
 Tue Apr  1 07:37:00 2014  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* addr2line.c (fill_lines): use dynsym, which is used for dynamic
diff --git a/parse.y b/parse.y
index 3f756ce8dc..680242daa0 100644
--- a/parse.y
+++ b/parse.y
@@ -10705,7 +10705,13 @@ rb_str_dynamic_intern(VALUE str)
     ID id, type;
 
     if (st_lookup(global_symbols.sym_id, str, &id)) {
-	return ID2SYM(id);
+	VALUE sym = ID2SYM(id);
+	if (!STATIC_SYM_P(sym)) {
+	    /* because of lazy sweep, dynamic symbol may be unmarked already and swept
+	     * at next time */
+	    rb_gc_resurrect(sym);
+	}
+	return sym;
     }
 
     enc = rb_enc_get(str);