diff --git a/vcr/cassette.py b/vcr/cassette.py
index 8e6816f..e478082 100644
--- a/vcr/cassette.py
+++ b/vcr/cassette.py
@@ -78,10 +78,13 @@ class Cassette(object):
     def responses_of(self, request):
         '''
         Find the responses corresponding to a request.
-	This function isn't actually used by VCR internally, but is
-	provided as an external API.
+        This function isn't actually used by VCR internally, but is
+        provided as an external API.
         '''
-        responses = [resp for req, resp in self.data if requests_match(req, request, self._match_on)]
+        responses = \
+            [resp for req, resp in self.data if
+                requests_match(req, request, self._match_on)]
+
         if responses:
             return responses
         # I decided that a KeyError is the best exception to raise
diff --git a/vcr/persisters/filesystem.py b/vcr/persisters/filesystem.py
index 7eb6109..9b00fa0 100644
--- a/vcr/persisters/filesystem.py
+++ b/vcr/persisters/filesystem.py
@@ -8,5 +8,5 @@ class FilesystemPersister(object):
         dirname, filename = os.path.split(cassette_path)
         if dirname and not os.path.exists(dirname):
             os.makedirs(dirname)
-	with open(cassette_path, 'w') as f:
-	    f.write(data)
+        with open(cassette_path, 'w') as f:
+            f.write(data)
diff --git a/vcr/stubs/__init__.py b/vcr/stubs/__init__.py
index 5eb7548..9871069 100644
--- a/vcr/stubs/__init__.py
+++ b/vcr/stubs/__init__.py
@@ -165,12 +165,17 @@ class VCRConnectionMixin:
         '''Retrieve a the response'''
         # Check to see if the cassette has a response for this request. If so,
         # then return it
-        if self._vcr_request in self.cassette and  self.cassette.record_mode != "all" and self.cassette.rewound:
+        if self._vcr_request in self.cassette and \
+                self.cassette.record_mode != "all" and \
+                self.cassette.rewound:
             response = self.cassette.play_response(self._vcr_request)
             return VCRHTTPResponse(response)
         else:
             if self.cassette.write_protected:
-                raise Exception("Can't overwrite existing cassette in your current record mode.")
+                raise Exception(
+                    "Can't overwrite existing cassette in \
+                     your current record mode."
+                )
 
             # Otherwise, we should send the request, then get the response
             # and return it.