diff --git a/vcr/cassette.py b/vcr/cassette.py
index 9122b4aa..0db98569 100644
--- a/vcr/cassette.py
+++ b/vcr/cassette.py
@@ -247,6 +247,8 @@ def _responses(self, request):
         the request.
         """
         request = self._before_record_request(request)
+        if request is None:
+            return
         for index, (stored_request, response) in enumerate(self.data):
             if requests_match(request, stored_request, self._match_on):
                 yield index, response
diff --git a/vcr/stubs/__init__.py b/vcr/stubs/__init__.py
index 8a1a16a4..ce3a501a 100644
--- a/vcr/stubs/__init__.py
+++ b/vcr/stubs/__init__.py
@@ -227,7 +227,7 @@ def getresponse(self, _=False, **kwargs):
             response = self.cassette.play_response(self._vcr_request)
             return VCRHTTPResponse(response)
         else:
-            if self.cassette.write_protected and self.cassette.filter_request(self._vcr_request):
+            if self.cassette.write_protected and self._vcr_request in self.cassette:
                 raise CannotOverwriteExistingCassetteException(
                     cassette=self.cassette, failed_request=self._vcr_request
                 )
diff --git a/vcr/stubs/aiohttp_stubs.py b/vcr/stubs/aiohttp_stubs.py
index f71b1394..3fbda860 100644
--- a/vcr/stubs/aiohttp_stubs.py
+++ b/vcr/stubs/aiohttp_stubs.py
@@ -269,7 +269,7 @@ async def new_request(self, method, url, **kwargs):
             self._cookie_jar.update_cookies(response.cookies, response.url)
             return response
 
-        if cassette.write_protected and cassette.filter_request(vcr_request):
+        if cassette.write_protected and vcr_request in cassette:
             raise CannotOverwriteExistingCassetteException(cassette=cassette, failed_request=vcr_request)
 
         log.info("%s not in cassette, sending to real server", vcr_request)
diff --git a/vcr/stubs/httpx_stubs.py b/vcr/stubs/httpx_stubs.py
index 803ddbe1..b3104339 100644
--- a/vcr/stubs/httpx_stubs.py
+++ b/vcr/stubs/httpx_stubs.py
@@ -83,7 +83,7 @@ def _shared_vcr_send(cassette, real_send, *args, **kwargs):
     if cassette.can_play_response_for(vcr_request):
         return vcr_request, _play_responses(cassette, real_request, vcr_request, args[0], kwargs)
 
-    if cassette.write_protected and cassette.filter_request(vcr_request):
+    if cassette.write_protected and vcr_request in cassette:
         raise CannotOverwriteExistingCassetteException(cassette=cassette, failed_request=vcr_request)
 
     _logger.info("%s not in cassette, sending to real server", vcr_request)
diff --git a/vcr/stubs/tornado_stubs.py b/vcr/stubs/tornado_stubs.py
index b482fd1f..7255888b 100644
--- a/vcr/stubs/tornado_stubs.py
+++ b/vcr/stubs/tornado_stubs.py
@@ -60,7 +60,7 @@ def new_fetch_impl(self, request, callback):
             )
             return callback(response)
         else:
-            if cassette.write_protected and cassette.filter_request(vcr_request):
+            if cassette.write_protected and vcr_request in cassette:
                 response = HTTPResponse(
                     request,
                     599,