2 files changed, 5 insertions, 4 deletions
diff --git a/class.c b/class.c
index ba57d8a39d..c31d1a9be7 100644
--- a/class.c
+++ b/class.c
@@ -700,7 +700,6 @@ class_alloc(VALUE flags, VALUE klass)
 
     RCLASS_SET_ORIGIN((VALUE)obj, (VALUE)obj);
     RCLASS_SET_REFINED_CLASS((VALUE)obj, Qnil);
-    RCLASS_SET_ALLOCATOR((VALUE)obj, 0);
 
     RCLASS_SET_SUBCLASSES((VALUE)obj, anchor);
 
@@ -1044,7 +1043,9 @@ rb_mod_init_copy(VALUE clone, VALUE orig)
         RBASIC_SET_CLASS(clone, rb_singleton_class_clone(orig));
         rb_singleton_class_attached(METACLASS_OF(clone), (VALUE)clone);
     }
-    RCLASS_SET_ALLOCATOR(clone, RCLASS_ALLOCATOR(orig));
+    if (BUILTIN_TYPE(clone) == T_CLASS) {
+        RCLASS_SET_ALLOCATOR(clone, RCLASS_ALLOCATOR(orig));
+    }
     copy_tables(clone, orig);
     if (RCLASS_M_TBL(orig)) {
         struct clone_method_arg arg;
@@ -1085,7 +1086,6 @@ rb_mod_init_copy(VALUE clone, VALUE orig)
             rb_class_set_super(prev_clone_p, clone_p);
             prev_clone_p = clone_p;
             RCLASS_SET_CONST_TBL(clone_p, RCLASS_CONST_TBL(p), false);
-            RCLASS_SET_ALLOCATOR(clone_p, RCLASS_ALLOCATOR(p));
             if (RB_TYPE_P(clone, T_CLASS)) {
                 RCLASS_SET_INCLUDER(clone_p, clone);
             }
diff --git a/internal/class.h b/internal/class.h
index 15530b8842..4a3e0afafb 100644
--- a/internal/class.h
+++ b/internal/class.h
@@ -667,7 +667,8 @@ RCLASS_ALLOCATOR(VALUE klass)
 static inline void
 RCLASS_SET_ALLOCATOR(VALUE klass, rb_alloc_func_t allocator)
 {
-    assert(!RCLASS_SINGLETON_P(klass));
+    RUBY_ASSERT(RB_TYPE_P(klass, T_CLASS));
+    RUBY_ASSERT(!RCLASS_SINGLETON_P(klass));
     RCLASS_EXT_PRIME(klass)->as.class.allocator = allocator; // Allocator is set only on the initial definition
 }