diff --git a/vm_method.c b/vm_method.c
index 0abef8f24b..c343015778 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -806,16 +806,17 @@ prepare_callable_method_entry(VALUE defined_class, ID id, const rb_method_entry_
 	VM_ASSERT(RB_TYPE_P(defined_class, T_ICLASS) || RB_TYPE_P(defined_class, T_MODULE));
 	VM_ASSERT(me->defined_class == 0);
 
-	if ((mtbl = RCLASS_CALLABLE_M_TBL(defined_class)) == NULL) {
-	    mtbl = RCLASS_EXT(defined_class)->callable_m_tbl = rb_id_table_create(0);
-	}
+	mtbl = RCLASS_CALLABLE_M_TBL(defined_class);
 
-	if (rb_id_table_lookup(mtbl, id, (VALUE *)&me)) {
+	if (mtbl && rb_id_table_lookup(mtbl, id, (VALUE *)&me)) {
 	    RB_DEBUG_COUNTER_INC(mc_cme_complement_hit);
 	    cme = (rb_callable_method_entry_t *)me;
 	    VM_ASSERT(callable_method_entry_p(cme));
 	}
 	else {
+	    if (!mtbl) {
+		mtbl = RCLASS_EXT(defined_class)->callable_m_tbl = rb_id_table_create(0);
+	    }
 	    cme = rb_method_entry_complement_defined_class(me, me->called_id, defined_class);
 	    rb_id_table_insert(mtbl, id, (VALUE)cme);
 	    VM_ASSERT(callable_method_entry_p(cme));