diff --git a/ChangeLog b/ChangeLog
index c28660890e..2091367a49 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul 13 10:33:29 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* array.c (rb_ary_flatten_bang): check argument if valid
+	  integer.  [ruby-dev:31197]
+
 Fri Jul 13 10:10:46 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb (link_command, cc_command, cpp_command): do not expand
diff --git a/array.c b/array.c
index 2dcb2b4856..67f472a826 100644
--- a/array.c
+++ b/array.c
@@ -1139,7 +1139,6 @@ each_i(VALUE ary)
 VALUE
 rb_ary_each(VALUE ary)
 {
-    VALUE val;
     RETURN_ENUMERATOR(ary, 0, 0);
     ITERATE(each_i, ary);
     return ary;
@@ -2842,7 +2841,7 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
     VALUE lv;
 
     rb_scan_args(argc, argv, "01", &lv);
-    if (!NIL_P(lv)) level = FIX2INT(lv);
+    if (!NIL_P(lv)) level = NUM2INT(lv);
     if (level == 0) return ary;
     while (i<RARRAY_LEN(ary)) {
 	VALUE ary2 = RARRAY_PTR(ary)[i];