--- src/pmc/parrotinterpreter.pmc.orig	2009-08-11 14:22:25.000000000 -0700
+++ src/pmc/parrotinterpreter.pmc	2009-08-11 13:57:31.000000000 -0700
@@ -90,14 +90,15 @@
                 PObj_is_class_TEST(s->vtables[i]->pmc_class)) {
                 STRING * const class_name =
                     VTABLE_get_string(s, s->vtables[i]->pmc_class);
-                PARROT_ASSERT(VTABLE_exists_keyed_str(d,
-                    d->class_hash, class_name));
 
-                VTABLE_delete_keyed_str(d, d->class_hash, class_name);
-
-                if (last_remove == i + 1) {
-                    --d->n_vtable_max;
-                    last_remove = i;
+                if (VTABLE_exists_keyed_str(d,
+                    d->class_hash, class_name)) {
+                    VTABLE_delete_keyed_str(d, d->class_hash, class_name);
+
+                    if (last_remove == i + 1) {
+                        --d->n_vtable_max;
+                        last_remove = i;
+                    }
                 }
             }
         }