2 files changed, 5 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 14956f84a2..a84743e6a1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon May 13 15:24:16 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (rb_data_object_alloc): check klass only if klass is not 0.
+
 Mon May 13 14:57:28 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (rb_data_object_alloc, rb_data_typed_object_alloc):
diff --git a/gc.c b/gc.c
index d0294cbc26..fbdc964514 100644
--- a/gc.c
+++ b/gc.c
@@ -716,7 +716,7 @@ VALUE
 rb_data_object_alloc(VALUE klass, void *datap, RUBY_DATA_FUNC dmark, RUBY_DATA_FUNC dfree)
 {
     NEWOBJ_OF(data, struct RData, klass, T_DATA);
-    Check_Type(klass, T_CLASS);
+    if (klass) Check_Type(klass, T_CLASS);
     data->data = datap;
     data->dfree = dfree;
     data->dmark = dmark;