diff --git a/test/ruby/test_complex.rb b/test/ruby/test_complex.rb
index b2894610f7..e364c97d9a 100644
--- a/test/ruby/test_complex.rb
+++ b/test/ruby/test_complex.rb
@@ -517,6 +517,23 @@ class Complex_Test < Test::Unit::TestCase
     assert_equal([Complex(2),Complex(1)], Complex(1).coerce(Complex(2)))
   end
 
+  class ObjectX
+    def + (x) Rational(1) end
+    alias - +
+    alias * +
+    alias / +
+    alias quo +
+    alias ** +
+    def coerce(x) [x, Complex(1)] end
+  end
+
+  def test_coerce2
+    x = ObjectX.new
+    %w(+ - * / quo **).each do |op|
+      assert_kind_of(Numeric, Complex(1).__send__(op, x))
+    end
+  end
+
   def test_unify
     if @unify
       assert_instance_of(Fixnum, Complex(1,2) + Complex(-1,-2))
@@ -1082,6 +1099,7 @@ class Complex_Test < Test::Unit::TestCase
       assert_equal(Complex(1), 1 ** Complex(1))
     end
     assert_equal('-1.0-0.0i', Complex(-1.0, -0.0).to_s)
+    assert_in_delta(Math::PI, Complex(-0.0).arg, 0.001)
   end
 
   def test_known_bug
diff --git a/test/ruby/test_rational.rb b/test/ruby/test_rational.rb
index cf88617990..8b992350ab 100644
--- a/test/ruby/test_rational.rb
+++ b/test/ruby/test_rational.rb
@@ -723,6 +723,26 @@ class Rational_Test < Test::Unit::TestCase
     assert_equal([Rational(2),Rational(1)], Rational(1).coerce(Rational(2)))
   end
 
+  class ObjectX
+    def + (x) Rational(1) end
+    alias - +
+    alias * +
+    alias / +
+    alias quo +
+    alias div +
+    alias % +
+    alias remainder +
+    alias ** +
+    def coerce(x) [x, Rational(1)] end
+  end
+
+  def test_coerce2
+    x = ObjectX.new
+    %w(+ - * / quo div % remainder **).each do |op|
+      assert_kind_of(Numeric, Rational(1).__send__(op, x))
+    end
+  end
+
   def test_unify
     if @unify
       assert_instance_of(Fixnum, Rational(1,2) + Rational(1,2))