diff --git a/lib/rspec/matchers/matcher.rb b/lib/rspec/matchers/matcher.rb
index afeb691a3..d597cb7c9 100644
--- a/lib/rspec/matchers/matcher.rb
+++ b/lib/rspec/matchers/matcher.rb
@@ -97,11 +97,9 @@ def diffable
       
       # See RSpec::Matchers
       def chain(method, &block)
-        self.class.class_eval do
-          define_method method do |*args|
-            block.call(*args)
-            self
-          end
+        define_method method do |*args|
+          block.call(*args)
+          self
         end
       end
       
diff --git a/spec/rspec/matchers/matcher_spec.rb b/spec/rspec/matchers/matcher_spec.rb
index 2fa95b02c..14fda407b 100644
--- a/spec/rspec/matchers/matcher_spec.rb
+++ b/spec/rspec/matchers/matcher_spec.rb
@@ -334,6 +334,14 @@ def assert_equal(a,b)
         matcher.expecting('value').matches?('other value').should be_false
       end
 
+      it "prevents name collisions on chainable methods from different matchers" do
+        m1 = RSpec::Matchers::Matcher.new(:m1) { chain(:foo) { raise "foo in m1" } }
+        m2 = RSpec::Matchers::Matcher.new(:m2) { chain(:foo) { raise "foo in m2" } }
+
+        expect { m1.foo }.to raise_error("foo in m1")
+        expect { m2.foo }.to raise_error("foo in m2")
+      end
+
       context "defined using the dsl" do
         def a_method_in_the_example
           "method defined in the example"