diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index 5a566879b7..dfe636045d 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -722,6 +722,27 @@ class TestFloat < Test::Unit::TestCase
     assert_equal(-7.1364, -7.1364499.round(4, half: :down))
   end
 
+  def test_round_half_nil
+    assert_equal(13.0, 12.5.round(half: nil))
+    assert_equal(14.0, 13.5.round(half: nil))
+
+    assert_equal(2.2, 2.15.round(1, half: nil))
+    assert_equal(2.3, 2.25.round(1, half: nil))
+    assert_equal(2.4, 2.35.round(1, half: nil))
+
+    assert_equal(-2.2, -2.15.round(1, half: nil))
+    assert_equal(-2.3, -2.25.round(1, half: nil))
+    assert_equal(-2.4, -2.35.round(1, half: nil))
+
+    assert_equal(7.1365, 7.13645.round(4, half: nil))
+    assert_equal(7.1365, 7.1364501.round(4, half: nil))
+    assert_equal(7.1364, 7.1364499.round(4, half: nil))
+
+    assert_equal(-7.1365, -7.13645.round(4, half: nil))
+    assert_equal(-7.1365, -7.1364501.round(4, half: nil))
+    assert_equal(-7.1364, -7.1364499.round(4, half: nil))
+  end
+
   def test_round_half_invalid
     assert_raise_with_message(ArgumentError, /Object/) {
       1.0.round(half: Object)