diff --git a/radicale/auth.py b/radicale/auth.py
index 2431aea..4e0aa7a 100644
--- a/radicale/auth.py
+++ b/radicale/auth.py
@@ -52,6 +52,7 @@ following significantly more secure schemes are parsable by Radicale:
 
 """
 
+import functools
 import base64
 import hashlib
 import os
@@ -102,15 +103,15 @@ class Auth(BaseAuth):
             self.verify = self._plain
         elif self.encryption == "md5":
             try:
-                from passlib.hash import apr_md5_crypt as _passlib_md5apr1
+                from passlib.hash import apr_md5_crypt
             except ImportError:
                 raise RuntimeError(
                     "The htpasswd encryption method 'md5' requires "
                     "the passlib module.")
-            self.verify = self._md5apr1
+            self.verify = functools.partial(self._md5apr1, apr_md5_crypt)
         elif self.encryption == "bcrypt":
             try:
-                from passlib.hash import bcrypt as _passlib_bcrypt
+                from passlib.hash import bcrypt
             except ImportError:
                 raise RuntimeError(
                     "The htpasswd encryption method 'bcrypt' requires "
@@ -118,8 +119,8 @@ class Auth(BaseAuth):
             # A call to `encrypt` raises passlib.exc.MissingBackendError with a
             # good error message if bcrypt backend is not available. Trigger
             # this here.
-            _passlib_bcrypt.encrypt("test-bcrypt-backend")
-            self.verify = self._bcrypt
+            bcrypt.encrypt("test-bcrypt-backend")
+            self.verify = functools.partial(self._bcrypt, bcrypt)
         elif self.encryption == "crypt":
             try:
                 import crypt
@@ -127,7 +128,7 @@ class Auth(BaseAuth):
                 raise RuntimeError(
                     "The htpasswd encryption method 'crypt' requires "
                     "the crypt() system support.")
-            self.verify = self._crypt
+            self.verify = functools.partial(self._crypt, crypt)
         else:
             raise RuntimeError(
                 "The htpasswd encryption method '%s' is not "
@@ -137,12 +138,10 @@ class Auth(BaseAuth):
         """Check if ``hash_value`` and ``password`` match, using plain method."""
         return hash_value == password
 
-
-    def _crypt(self, hash_value, password):
+    def _crypt(self, crypt, hash_value, password):
         """Check if ``hash_value`` and ``password`` match, using crypt method."""
         return crypt.crypt(password, hash_value) == hash_value
 
-
     def _sha1(self, hash_value, password):
         """Check if ``hash_value`` and ``password`` match, using sha1 method."""
         hash_value = hash_value.replace("{SHA}", "").encode("ascii")
@@ -151,7 +150,6 @@ class Auth(BaseAuth):
         sha1.update(password)
         return sha1.digest() == base64.b64decode(hash_value)
 
-
     def _ssha(self, hash_salt_value, password):
         """Check if ``hash_salt_value`` and ``password`` match, using salted sha1
         method. This method is not directly supported by htpasswd, but it can be
@@ -166,13 +164,11 @@ class Auth(BaseAuth):
         sha1.update(salt_value)
         return sha1.digest() == hash_value
 
+    def _bcrypt(self, bcrypt, hash_value, password):
+        return bcrypt.verify(password, hash_value)
 
-    def _bcrypt(self, hash_value, password):
-        return _passlib_bcrypt.verify(password, hash_value)
-
-
-    def _md5apr1(self, hash_value, password):
-        return _passlib_md5apr1.verify(password, hash_value)
+    def _md5apr1(self, md5_apr1, hash_value, password):
+        return md5_apr1.verify(password, hash_value)
 
     def is_authenticated(self, user, password):
         # The content of the file is not cached because reading is generally a
@@ -186,4 +182,3 @@ class Auth(BaseAuth):
                     if login == user:
                         return self.verify(hash_value, password)
         return False
-
diff --git a/radicale/storage.py b/radicale/storage.py
index 41dd838..982026f 100644
--- a/radicale/storage.py
+++ b/radicale/storage.py
@@ -45,6 +45,7 @@ def load(configuration, logger):
         collection_class = Collection
     else:
         collection_class = import_module(storage_type).Collection
+
     class CollectionCopy(collection_class):
         """Collection copy, avoids overriding the original class attributes."""
     CollectionCopy.configuration = configuration
diff --git a/tox.ini b/tox.ini
index eef0df9..9a74e90 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,9 +7,12 @@ deps =
   nose-cov
   pam
   requests
+  flake8
 
 [testenv]
-commands = nosetests []
+commands =
+  flake8
+  nosetests []
 
 [testenv:py33]
 deps =
@@ -25,3 +28,6 @@ deps =
 deps =
   git+https://github.com/eberle1080/dulwich-py3k.git
   {[base]deps}
+
+[flake8]
+max-line-length = 100