diff --git a/CHANGELOG.md b/CHANGELOG.md
index c21390705..fe4a3a5f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Master
+
+* `assert_requested` and `assert_not_requested` raise an error if a stub object is provided together with a block.
+
 ## 1.9.3
 
 * Fixed issue with unavailable constant Mutex in Ruby < 1.9
diff --git a/lib/webmock/api.rb b/lib/webmock/api.rb
index f6ce84427..1275aafb4 100644
--- a/lib/webmock/api.rb
+++ b/lib/webmock/api.rb
@@ -21,15 +21,19 @@ class << self
     def assert_requested(*args, &block)
       if not args[0].is_a?(WebMock::RequestStub)
         args = convert_uri_method_and_options_to_request_and_options(*args, &block)
+      elsif block
+        raise ArgumentError, "assert_requested with a stub object, doesn't accept blocks"
       end
-      assert_request_requested(*args, &block)
+      assert_request_requested(*args)
     end
 
     def assert_not_requested(*args, &block)
       if not args[0].is_a?(WebMock::RequestStub)
         args = convert_uri_method_and_options_to_request_and_options(*args, &block)
+      elsif block
+        raise ArgumentError, "assert_not_requested with a stub object, doesn't accept blocks"
       end
-      assert_request_not_requested(*args, &block)
+      assert_request_not_requested(*args)
     end
 
     def hash_including(expected)
diff --git a/test/shared_test.rb b/test/shared_test.rb
index ff70fe8de..f73294551 100644
--- a/test/shared_test.rb
+++ b/test/shared_test.rb
@@ -9,6 +9,18 @@ def setup
     @stub_https = stub_http_request(:any, "https://www.example.com")
   end
 
+  def test_assert_requested_with_stub_and_block_raises_error
+    assert_raise ArgumentError do
+      assert_requested(@stub_http) {}
+    end
+  end
+
+  def test_assert_not_requested_with_stub_and_block_raises_error
+    assert_raise ArgumentError do
+      assert_not_requested(@stub_http) {}
+    end
+  end
+
   def test_error_on_non_stubbed_request
     default_ruby_headers = (RUBY_VERSION >= "1.9.1") ? "{'Accept'=>'*/*', 'User-Agent'=>'Ruby'}" : "{'Accept'=>'*/*'}"
     assert_raise_with_message(WebMock::NetConnectNotAllowedError, %r{Real HTTP connections are disabled. Unregistered request: GET http://www.example.net/ with headers}) do