diff --git a/activesupport/lib/active_support/core_ext/test/difference.rb b/activesupport/lib/active_support/core_ext/test/difference.rb
index 3d75809c6914f410e393a373e71abf5fb83c52b8..2ae4b7d6d1f0bc94135de390cd9cdd8fc6b85c9e 100644
--- a/activesupport/lib/active_support/core_ext/test/difference.rb
+++ b/activesupport/lib/active_support/core_ext/test/difference.rb
@@ -1,6 +1,7 @@
 module Test #:nodoc:
   module Unit #:nodoc:
-    module Assertions #:nodoc:      
+    # FIXME: no Proc#binding in Ruby 2, must change this API
+    module Assertions #:nodoc:
       # Test numeric difference between the return value of an expression as a result of what is evaluated
       # in the yielded block.
       #
diff --git a/activesupport/test/test_test.rb b/activesupport/test/test_test.rb
index 944b98f529ded3dcf91e4af66f1873bd3f5c4b4d..5c8039ea1eca5e0252dc6761ae5a788308081568 100644
--- a/activesupport/test/test_test.rb
+++ b/activesupport/test/test_test.rb
@@ -1,7 +1,6 @@
 require File.dirname(__FILE__) + '/abstract_unit'
 
 class AssertDifferenceTest < Test::Unit::TestCase
-  
   def setup
     @object = Class.new do
       attr_accessor :num 
@@ -15,48 +14,52 @@ def decrement
     end.new    
     @object.num = 0
   end
-  
-  def test_assert_no_difference
-    assert_no_difference '@object.num' do
-      # ...
+
+  if lambda { }.respond_to?(:binding)
+    def test_assert_no_difference
+      assert_no_difference '@object.num' do
+        # ...
+      end
     end
-  end
 
-  def test_assert_difference
-    assert_difference '@object.num', +1 do
-      @object.increment
+    def test_assert_difference
+      assert_difference '@object.num', +1 do
+        @object.increment
+      end
     end
-  end
 
-  def test_assert_difference_with_implicit_difference
-    assert_difference '@object.num' do
-      @object.increment
+    def test_assert_difference_with_implicit_difference
+      assert_difference '@object.num' do
+        @object.increment
+      end
     end
-  end
 
-  def test_arbitrary_expression
-    assert_difference '@object.num + 1', +2 do
-      @object.increment
-      @object.increment
+    def test_arbitrary_expression
+      assert_difference '@object.num + 1', +2 do
+        @object.increment
+        @object.increment
+      end
     end
-  end
 
-  def test_negative_differences
-    assert_difference '@object.num', -1 do
-      @object.decrement
+    def test_negative_differences
+      assert_difference '@object.num', -1 do
+        @object.decrement
+      end
     end
-  end
 
-  def test_expression_is_evaluated_in_the_appropriate_scope
-    local_scope = 'foo'
-    silence_warnings do
-      assert_difference('local_scope; @object.num') { @object.increment }
+    def test_expression_is_evaluated_in_the_appropriate_scope
+      local_scope = 'foo'
+      silence_warnings do
+        assert_difference('local_scope; @object.num') { @object.increment }
+      end
     end
-  end
-  
-  def test_array_of_expressions
-    assert_difference [ '@object.num', '@object.num + 1' ], +1 do
-      @object.increment
+
+    def test_array_of_expressions
+      assert_difference [ '@object.num', '@object.num + 1' ], +1 do
+        @object.increment
+      end
     end
+  else
+    def default_test; end
   end
 end