diff --git a/ChangeLog b/ChangeLog
index c4290f4481..c4c9007b14 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Mar  5 12:24:23 2013  Eric Hodel  <drbrain@segment7.net>
+
+	* enumerator.c (enumerator_with_index):  Restore handling of a nil memo
+	  from r39594.
+
 Tue Mar  5 10:40:22 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/objspace/objspace.c (count_nodes): count also newly added nodes,
diff --git a/enumerator.c b/enumerator.c
index bd039d28bc..7143e37636 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -492,6 +492,8 @@ enumerator_with_index(int argc, VALUE *argv, VALUE obj)
 
     rb_scan_args(argc, argv, "01", &memo);
     RETURN_SIZED_ENUMERATOR(obj, argc, argv, enumerator_size);
+    if (NIL_P(memo))
+	memo = INT2NUM(0);
     return enumerator_block_call(obj, enumerator_with_index_i, (VALUE)&memo);
 }