diff --git a/object.c b/object.c
index 572bfd5a5b..3bc6725552 100644
--- a/object.c
+++ b/object.c
@@ -36,6 +36,7 @@
 #include "ruby/encoding.h"
 #include "ruby/st.h"
 #include "ruby/util.h"
+#include "ruby/assert.h"
 #include "builtin.h"
 
 /*!
@@ -324,12 +325,8 @@ rb_obj_singleton_class(VALUE obj)
 MJIT_FUNC_EXPORTED void
 rb_obj_copy_ivar(VALUE dest, VALUE obj)
 {
-    if (!(RBASIC(dest)->flags & ROBJECT_EMBED) && ROBJECT_IVPTR(dest)) {
-	xfree(ROBJECT_IVPTR(dest));
-	ROBJECT(dest)->as.heap.ivptr = 0;
-	ROBJECT(dest)->as.heap.numiv = 0;
-	ROBJECT(dest)->as.heap.iv_index_tbl = 0;
-    }
+    RUBY_ASSERT(RBASIC(dest)->flags & ROBJECT_EMBED);
+
     if (RBASIC(obj)->flags & ROBJECT_EMBED) {
 	MEMCPY(ROBJECT(dest)->as.ary, ROBJECT(obj)->as.ary, VALUE, ROBJECT_EMBED_LEN_MAX);
 	RBASIC(dest)->flags |= ROBJECT_EMBED;