diff --git a/lib/flexmock/argument_matchers.rb b/lib/flexmock/argument_matchers.rb
index c5b3da0..9bf76d8 100644
--- a/lib/flexmock/argument_matchers.rb
+++ b/lib/flexmock/argument_matchers.rb
@@ -67,6 +67,23 @@ def inspect
     end
   end
 
+  ####################################################################
+  # Match hashes that match all the fields of +hash+.
+  class KwArgsMatcher
+    def initialize(expected)
+      @expected = expected
+    end
+    def ===(target)
+      return false unless target.kind_of?(Hash)
+      return false unless @expected.all? { |k, v| v === target[k] }
+
+      @expected.size == target.size
+    end
+    def inspect
+      "kw(#{@expected.inspect})"
+    end
+  end
+
   ####################################################################
   # Match objects that implement all the methods in +methods+.
   class DuckMatcher
diff --git a/lib/flexmock/expectation.rb b/lib/flexmock/expectation.rb
index b8058c3..1b514d1 100644
--- a/lib/flexmock/expectation.rb
+++ b/lib/flexmock/expectation.rb
@@ -241,7 +241,12 @@ def with_any_args
     # Declare that the method can be called with any number of
     # arguments of any type.
     def with_kw_args(matcher)
-      @expected_kw_args = matcher
+      @expected_kw_args =
+        if matcher.kind_of?(Hash)
+          KwArgsMatcher.new(matcher)
+        else
+          matcher
+        end
       self
     end
 
diff --git a/test/should_receive_test.rb b/test/should_receive_test.rb
index f2ec04d..54fa51d 100644
--- a/test/should_receive_test.rb
+++ b/test/should_receive_test.rb
@@ -446,6 +446,32 @@ def test_with_kw_args_matching
     end
   end
 
+  def test_with_kw_args_matches_values_separately
+    FlexMock.use('greeter') do |m|
+      m.should_receive(:hi).with_kw_args(a: on { |v| v == 1 }, b: 2).once
+      m.hi(a: 1, b: 2)
+    end
+  end
+
+  def test_with_kw_args_raises_if_an_expected_key_is_missing
+    assert_raises(FlexMock::CheckFailedError) do
+      FlexMock.use('greeter') do |m|
+        m.should_receive(:hi).with_kw_args(a: on { |v| v == 1 }, b: 2).once
+        m.hi(a: 1)
+      end
+    end
+  end
+
+  def test_with_kw_args_raises_if_there_is_an_actual_key_too_much
+    assert_raises(FlexMock::CheckFailedError) do
+      FlexMock.use('greeter') do |m|
+        m.should_receive(:hi).with_kw_args(a: on { |v| v == 1 }, b: 2).once
+        m.hi(a: 1, b: 2, c: 3)
+      end
+    end
+  end
+
+
   def test_with_kw_args_non_matching
     FlexMock.use('greeter') do |m|
       m.should_receive(:hi).with(20).with_kw_args(some: 10)