diff a/src/hotspot/share/gc/g1/g1FullGCMarker.inline.hpp b/src/hotspot/share/gc/g1/g1FullGCMarker.inline.hpp
--- a/src/hotspot/share/gc/g1/g1FullGCMarker.inline.hpp
+++ b/src/hotspot/share/gc/g1/g1FullGCMarker.inline.hpp
@@ -163,11 +163,17 @@
     }
   } while (!is_empty());
 }
 
 inline void G1FullGCMarker::follow_klass(Klass* k) {
-  oop op = k->class_loader_data()->holder_no_keepalive();
+  ClassLoaderData* cld = k->class_loader_data();
+#if 0 // IOITMP
+  if (cld == NULL) {
+    return;
+  }
+#endif
+  oop op = cld->holder_no_keepalive();
   mark_and_push(&op);
 }
 
 inline void G1FullGCMarker::follow_cld(ClassLoaderData* cld) {
   _cld_closure.do_cld(cld);