1 files changed, 1 insertions, 1 deletions
diff --git a/gc.c b/gc.c
index c221773df9..9e6a8f3d85 100644
--- a/gc.c
+++ b/gc.c
@@ -398,7 +398,7 @@ rb_data_object_alloc(klass, datap, dmark, dfree)
     RUBY_DATA_FUNC dfree;
 {
     NEWOBJ(data, struct RData);
-    Check_Type(klass, T_CLASS);
+    if (klass) Check_Type(klass, T_CLASS);
     OBJSETUP(data, klass, T_DATA);
     data->data = datap;
     data->dfree = dfree;