Check for the right exception

activemodel/test/cases/type/unsigned_integer_test.rb

@@ -9,7 +9,7 @@ class UnsignedIntegerTest < ActiveModel::TestCase
       end
 
       test "minus value is out of range" do
-        assert_raises(::RangeError) do
+        assert_raises(ActiveModel::RangeError) do
           UnsignedInteger.new.serialize(-1)
         end
       end