diff --git a/README.md b/README.md
index 2688c30..40710f6 100644
--- a/README.md
+++ b/README.md
@@ -115,9 +115,10 @@ proxy.stub('https://example.com/proc/').and_return(Proc.new { |params, headers,
 # You can also use Puffing Billy to intercept requests and responses. Just pass
 # a Proc and use the pass_request method. You can manipulate the request
 # (headers, URL, HTTP method, etc) and also the response from the upstream
-# server.
+# server. The scope of the delivered callable is the user scope where
+# it was defined.
 proxy.stub('http://example.com/').and_return(Proc.new { |*args|
-  response = pass_request(*args)
+  response = Billy.pass_request(*args)
   response[:headers]['Content-Type'] = 'text/plain'
   response[:body] = 'Hello World!'
   response[:code] = 200
diff --git a/lib/billy.rb b/lib/billy.rb
index d37b76c..839829a 100644
--- a/lib/billy.rb
+++ b/lib/billy.rb
@@ -28,4 +28,18 @@ def self.proxy
   def self.certificate_authority
     @certificate_authority ||= Billy::Authority.new
   end
+
+  # This global shortcut can be used inside of request stubs. You can modify
+  # the request beforehand and/or modify the actual response which is passed
+  # back by this method. But you can also implement a custom proxy passing
+  # method if you like to. This is just a shortcut.
+  def self.pass_request(params, headers, body, url, method)
+      handler = proxy.request_handler.handlers[:proxy]
+      response = handler.handle_request(method, url, headers, body)
+      {
+        code: response[:status],
+        body: response[:content],
+        headers: response[:headers]
+      }
+  end
 end
diff --git a/lib/billy/proxy_request_stub.rb b/lib/billy/proxy_request_stub.rb
index d98cd22..feb93f2 100644
--- a/lib/billy/proxy_request_stub.rb
+++ b/lib/billy/proxy_request_stub.rb
@@ -21,7 +21,7 @@ def call(method, url, params, headers, body)
       push_request(method, url, params, headers, body)
 
       if @response.respond_to?(:call)
-        res = instance_exec(params, headers, body, url, method, &@response)
+        res = @response.call(params, headers, body, url, method)
       else
         res = @response
       end
@@ -71,16 +71,6 @@ def matches?(method, url)
       end
     end
 
-    def pass_request(params, headers, body, url, method)
-      handler = Billy.proxy.request_handler.handlers[:proxy]
-      response = handler.handle_request(method, url, headers, body)
-      {
-        code: response[:status],
-        body: response[:content],
-        headers: response[:headers]
-      }
-    end
-
     private
 
     attr_writer :requests
diff --git a/spec/features/examples/tumblr_api_spec.rb b/spec/features/examples/tumblr_api_spec.rb
index cb2d117..054024e 100644
--- a/spec/features/examples/tumblr_api_spec.rb
+++ b/spec/features/examples/tumblr_api_spec.rb
@@ -1,24 +1,6 @@
 require 'spec_helper'
 
-describe 'Tumblr API example', type: :feature, js: true do
-  before do
-    proxy.stub('http://blog.howmanyleft.co.uk/api/read/json').and_return(
-      jsonp: {
-        posts: [
-          {
-            'regular-title' => 'News Item 1',
-            'url-with-slug' => 'http://example.com/news/1',
-            'regular-body' => 'News item 1 content here'
-          },
-          {
-            'regular-title' => 'News Item 2',
-            'url-with-slug' => 'http://example.com/news/2',
-            'regular-body' => 'News item 2 content here'
-          }
-        ]
-      })
-  end
-
+RSpec.shared_examples 'tumblr/expectations' do
   it 'should show news stories' do
     visit '/tumblr_api.html'
     expect(page).to have_link('News Item 1', href: 'http://example.com/news/1')
@@ -27,3 +9,51 @@
     expect(page).to have_content('News item 2 content here')
   end
 end
+
+describe 'Tumblr API example', type: :feature, js: true do
+  context 'without scope external references' do
+    before do
+      proxy.stub('http://blog.howmanyleft.co.uk/api/read/json').and_return(
+        jsonp: {
+          posts: [
+            {
+              'regular-title' => 'News Item 1',
+              'url-with-slug' => 'http://example.com/news/1',
+              'regular-body' => 'News item 1 content here'
+            },
+            {
+              'regular-title' => 'News Item 2',
+              'url-with-slug' => 'http://example.com/news/2',
+              'regular-body' => 'News item 2 content here'
+            }
+          ]
+        })
+    end
+
+    include_examples 'tumblr/expectations'
+  end
+
+  context 'with scope external references' do
+    let(:posts) do
+      [
+        {
+          'regular-title' => 'News Item 1',
+          'url-with-slug' => 'http://example.com/news/1',
+          'regular-body' => 'News item 1 content here'
+        },
+        {
+          'regular-title' => 'News Item 2',
+          'url-with-slug' => 'http://example.com/news/2',
+          'regular-body' => 'News item 2 content here'
+        }
+      ]
+    end
+
+    before do
+      proxy.stub('http://blog.howmanyleft.co.uk/api/read/json')
+           .and_return(proc { { jsonp: { posts: posts } } })
+    end
+
+    include_examples 'tumblr/expectations'
+  end
+end
diff --git a/spec/lib/billy/proxy_request_stub_spec.rb b/spec/lib/billy/proxy_request_stub_spec.rb
index 7a52348..bcb24ff 100644
--- a/spec/lib/billy/proxy_request_stub_spec.rb
+++ b/spec/lib/billy/proxy_request_stub_spec.rb
@@ -157,9 +157,6 @@
       expected_headers = { 'header1' => 'three', 'header2' => 'four' }
       expected_body = 'body text'
 
-      # Required due to the instance_exec implementation
-      subject.extend(RSpec::Matchers)
-
       subject.and_return(proc do |params, headers, body, url, method|
         expect(params).to eql expected_params
         expect(headers).to eql expected_headers
@@ -175,15 +172,12 @@
       ]
     end
 
-    it 'should use a callable with pass_request' do
+    it 'should use a callable with Billy.pass_request' do
       # Add the missing em-synchrony call which is done by
       # ProxyConnection#handle_request instead.
       EM.synchrony do
-        # Required due to the instance_exec implementation
-        subject.extend(RSpec::Matchers)
-
         subject.and_return(proc do |*args|
-          response = pass_request(*args)
+          response = Billy.pass_request(*args)
           response[:body] = 'modified'
           response[:code] = 205
           response