diff --git a/lib/cancan/controller_additions.rb b/lib/cancan/controller_additions.rb
index b4e9054..f86e77a 100644
--- a/lib/cancan/controller_additions.rb
+++ b/lib/cancan/controller_additions.rb
@@ -151,6 +151,20 @@ module CanCan
       def authorize_resource(*args)
         ControllerResource.add_before_filter(self, :authorize_resource, *args)
       end
+
+      def skip_authorization(*args)
+        self.before_filter(*args) do |controller|
+          controller.instance_variable_set(:@_authorized, true)
+        end
+      end
+
+      def check_authorization(*args)
+        self.after_filter(*args) do |controller|
+          unless controller.instance_variable_defined?(:@_authorized)
+            raise AuthorizationNotPerformed, "This action does not authorize the user. Add authorize! or authorize_resource to the controller."
+          end
+        end
+      end
     end
 
     def self.included(base)
@@ -186,6 +200,7 @@ module CanCan
     # See the load_and_authorize_resource method to automatically add the authorize! behavior
     # to the default RESTful actions.
     def authorize!(*args)
+      @_authorized = true
       current_ability.authorize!(*args)
     end
 
diff --git a/lib/cancan/exceptions.rb b/lib/cancan/exceptions.rb
index 177584f..c9deb1f 100644
--- a/lib/cancan/exceptions.rb
+++ b/lib/cancan/exceptions.rb
@@ -5,6 +5,9 @@ module CanCan
   # Raised when removed code is called, an alternative solution is provided in message.
   class ImplementationRemoved < Error; end
 
+  # Raised when using check_authorization without calling authorized!
+  class AuthorizationNotPerformed < Error; end
+
   # This error is raised when a user isn't allowed to access a given controller action.
   # This usually happens within a call to ControllerAdditions#authorize! but can be
   # raised manually.
diff --git a/spec/cancan/ability_spec.rb b/spec/cancan/ability_spec.rb
index 94037f5..a07b56e 100644
--- a/spec/cancan/ability_spec.rb
+++ b/spec/cancan/ability_spec.rb
@@ -265,6 +265,34 @@ describe CanCan::Ability do
     @ability.attributes_for(:new, Range).should == {:foo => "foo", :bar => 123, :baz => "baz"}
   end
 
+  it "should raise access denied exception if ability us unauthorized to perform a certain action" do
+    begin
+      @ability.authorize! :read, :foo, 1, 2, 3, :message => "Access denied!"
+    rescue CanCan::AccessDenied => e
+      e.message.should == "Access denied!"
+      e.action.should == :read
+      e.subject.should == :foo
+    else
+      fail "Expected CanCan::AccessDenied exception to be raised"
+    end
+  end
+
+  it "should not raise access denied exception if ability is authorized to perform an action" do
+    @ability.can :read, :foo
+    lambda { @ability.authorize!(:read, :foo) }.should_not raise_error
+  end
+
+  it "should raise access denied exception with default message if not specified" do
+    begin
+      @ability.authorize! :read, :foo
+    rescue CanCan::AccessDenied => e
+      e.default_message = "Access denied!"
+      e.message.should == "Access denied!"
+    else
+      fail "Expected CanCan::AccessDenied exception to be raised"
+    end
+  end
+
   describe "unauthorized message" do
     after(:each) do
       I18n.backend = nil
diff --git a/spec/cancan/controller_additions_spec.rb b/spec/cancan/controller_additions_spec.rb
index 4385e12..8d514aa 100644
--- a/spec/cancan/controller_additions_spec.rb
+++ b/spec/cancan/controller_additions_spec.rb
@@ -14,33 +14,10 @@ describe CanCan::ControllerAdditions do
     lambda { @controller.unauthorized! }.should raise_error(CanCan::ImplementationRemoved)
   end
 
-  it "should raise access denied exception if ability us unauthorized to perform a certain action" do
-    # TODO this should probably be moved into Ability spec
-    begin
-      @controller.authorize! :read, :foo, 1, 2, 3, :message => "Access denied!"
-    rescue CanCan::AccessDenied => e
-      e.message.should == "Access denied!"
-      e.action.should == :read
-      e.subject.should == :foo
-    else
-      fail "Expected CanCan::AccessDenied exception to be raised"
-    end
-  end
-
-  it "should not raise access denied exception if ability is authorized to perform an action" do
-    @controller.current_ability.can :read, :foo
-    lambda { @controller.authorize!(:read, :foo) }.should_not raise_error
-  end
-
-  it "should raise access denied exception with default message if not specified" do
-    begin
-      @controller.authorize! :read, :foo
-    rescue CanCan::AccessDenied => e
-      e.default_message = "Access denied!"
-      e.message.should == "Access denied!"
-    else
-      fail "Expected CanCan::AccessDenied exception to be raised"
-    end
+  it "authorize! should assign @_authorized instance variable and pass args to current ability" do
+    mock(@controller.current_ability).authorize!(:foo, :bar)
+    @controller.authorize!(:foo, :bar)
+    @controller.instance_variable_get(:@_authorized).should be_true
   end
 
   it "should have a current_ability method which generates an ability for the current user" do
@@ -76,4 +53,25 @@ describe CanCan::ControllerAdditions do
     mock(@controller_class).before_filter(:only => [:show, :index]) { |options, block| block.call(@controller) }
     @controller_class.load_resource :foo => :bar, :only => [:show, :index]
   end
+
+  it "skip_authorization should set up a before filter which sets @_authorized to true" do
+    mock(@controller_class).before_filter(:filter_options) { |options, block| block.call(@controller) }
+    @controller_class.skip_authorization(:filter_options)
+    @controller.instance_variable_get(:@_authorized).should be_true
+  end
+
+  it "check_authorization should trigger AuthorizationNotPerformed in after filter" do
+    mock(@controller_class).after_filter(:some_options) { |options, block| block.call(@controller) }
+    lambda {
+      @controller_class.check_authorization(:some_options)
+    }.should raise_error(CanCan::AuthorizationNotPerformed)
+  end
+
+  it "check_authorization should not raise error when @_authorized is set" do
+    @controller.instance_variable_set(:@_authorized, true)
+    mock(@controller_class).after_filter(:some_options) { |options, block| block.call(@controller) }
+    lambda {
+      @controller_class.check_authorization(:some_options)
+    }.should_not raise_error(CanCan::AuthorizationNotPerformed)
+  end
 end