1 files changed, 10 insertions, 0 deletions
diff --git a/spec/rubyspec/core/rational/to_r_spec.rb b/spec/rubyspec/core/rational/to_r_spec.rb
index 22c8b4532c..6e44cf1b23 100644
--- a/spec/rubyspec/core/rational/to_r_spec.rb
+++ b/spec/rubyspec/core/rational/to_r_spec.rb
@@ -7,4 +7,14 @@ describe "Rational#to_r" do
     obj = BasicObject.new
     lambda { Rational(obj) }.should raise_error(TypeError)
   end
+
+  it "works when a BasicObject has to_r" do
+    obj = BasicObject.new; def obj.to_r; 1 / 2.to_r end
+    Rational(obj).should == Rational('1/2')
+  end
+
+  it "fails when a BasicObject's to_r does not return a Rational" do
+    obj = BasicObject.new; def obj.to_r; 1 end
+    lambda { Rational(obj) }.should raise_error(TypeError)
+  end
 end