diff --git a/ChangeLog b/ChangeLog
index a946be29da..76bedc3a64 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Jul 21 23:47:38 2009  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* random.c (rand_init): array length of random seed was broken, which
+	  causes memory error with srand(2**1000000-1).
+
+	* test/ruby/test_rand.c: test for above.
+
 Tue Jul 21 21:37:19 2009  Keiju Ishitsuka  <keiju@emperor2.pendome>
 
 	* lib/irb/cmd/help.rb: fixed irb's "help" command. [ruby-core:22310].
diff --git a/random.c b/random.c
index e128c61e5f..ddaaedc5a8 100644
--- a/random.c
+++ b/random.c
@@ -304,11 +304,9 @@ rand_init(struct MT *mt, VALUE vseed)
 	if (blen == 0) {
 	    len = 1;
 	}
-	else if (blen > MT_MAX_STATE * SIZEOF_INT32 / SIZEOF_BDIGITS) {
-	    blen = (len = MT_MAX_STATE) * SIZEOF_INT32 / SIZEOF_BDIGITS;
-	    len = roomof(len, SIZEOF_INT32);
-	}
 	else {
+	    if (blen > MT_MAX_STATE * SIZEOF_INT32 / SIZEOF_BDIGITS)
+		blen = (len = MT_MAX_STATE) * SIZEOF_INT32 / SIZEOF_BDIGITS;
 	    len = roomof((int)blen * SIZEOF_BDIGITS, SIZEOF_INT32);
 	}
 	/* allocate ints for init_by_array */
diff --git a/test/ruby/test_rand.rb b/test/ruby/test_rand.rb
index 7bfd96f355..140851d5ba 100644
--- a/test/ruby/test_rand.rb
+++ b/test/ruby/test_rand.rb
@@ -164,4 +164,9 @@ class TestRand < Test::Unit::TestCase
     srand(0)
     assert_equal([1,4,2,5,3], [1,2,3,4,5].shuffle)
   end
+
+  def test_big_seed
+    srand(2**1000000-1)
+    assert_equal(1143843490, rand(0x100000000))
+  end
 end