diff --git a/test/ruby/test_fixnum.rb b/test/ruby/test_fixnum.rb
index 57999d4b03..4cf73fb4c8 100644
--- a/test/ruby/test_fixnum.rb
+++ b/test/ruby/test_fixnum.rb
@@ -23,4 +23,14 @@ class TestFixnum < Test::Unit::TestCase
       end
     end
   end
+
+  def test_succ
+    assert_equal(0x40000000, 0x3fffffff.succ, "[ruby-dev:31189]")
+    assert_equal(0x4000000000000000, 0x3fffffffffffffff.succ, "[ruby-dev:31190]")
+  end
+
+  def test_plus
+    assert_equal(0x4000000000000000, 0x3fffffffffffffff+1)
+  end
+
 end
diff --git a/test/ruby/test_range.rb b/test/ruby/test_range.rb
index 31f7e29de4..3c24215c6a 100644
--- a/test/ruby/test_range.rb
+++ b/test/ruby/test_range.rb
@@ -50,5 +50,7 @@ class TestRange < Test::Unit::TestCase
     assert_equal(2.0, (1.0..2.0).max)
     assert_equal(nil, (2.0..1.0).max)
     assert_raise(TypeError) { (1.0...2.0).max }
+
+    assert_equal(-0x80000002, ((-0x80000002)...(-0x80000001)).max)
   end
 end