diff --git a/ChangeLog b/ChangeLog
index 4c79830f5a..bc9d742fff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sat Dec 22 00:28:46 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* object.c (rb_obj_hash): shouldn't assume object_id can be long.
+	  based on a patch by Heesob Park at [ruby-core:51060].
+	  cf. [Backport #7454]
+
 Fri Dec 21 23:15:25 2012  Kouhei Sutou  <kou@cozmixng.org>
 
 	* ext/fiddle/lib/fiddle/struct.rb (Fiddle::CStructEntity#set_ctypes):
diff --git a/object.c b/object.c
index b05b41be25..13765bc621 100644
--- a/object.c
+++ b/object.c
@@ -125,7 +125,14 @@ VALUE
 rb_obj_hash(VALUE obj)
 {
     VALUE oid = rb_obj_id(obj);
-    st_index_t h = rb_hash_end(rb_hash_start(NUM2LONG(oid)));
+#if SIZEOF_LONG == SIZEOF_VOIDP
+    st_index_t index = NUM2LONG(oid);
+#elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
+    st_index_t index = NUM2LL(oid);
+#else
+# error not supported
+#endif
+    st_index_t h = rb_hash_end(rb_hash_start(index));
     return LONG2FIX(h);
 }