diff --git a/passbook/oauth_client/source_types/discord.py b/passbook/oauth_client/source_types/discord.py
index 6052e519e..4a0daad17 100644
--- a/passbook/oauth_client/source_types/discord.py
+++ b/passbook/oauth_client/source_types/discord.py
@@ -2,7 +2,6 @@
 import json
 from logging import getLogger
 
-from django.contrib.auth import get_user_model
 from requests.exceptions import RequestException
 
 from passbook.oauth_client.clients import OAuth2Client
@@ -50,12 +49,11 @@ class DiscordOAuth2Callback(OAuthCallback):
     client_class = DiscordOAuth2Client
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('username'),
+            'username': info.get('username'),
             'email': info.get('email', 'None'),
             'first_name': info.get('username'),
             'password': None,
         }
-        discord_user = user_get_or_create(user_model=user, **user_data)
+        discord_user = user_get_or_create(**user_data)
         return discord_user
diff --git a/passbook/oauth_client/source_types/facebook.py b/passbook/oauth_client/source_types/facebook.py
index 143d32bc4..57a3dc277 100644
--- a/passbook/oauth_client/source_types/facebook.py
+++ b/passbook/oauth_client/source_types/facebook.py
@@ -1,7 +1,5 @@
 """Facebook OAuth Views"""
 
-from django.contrib.auth import get_user_model
-
 from passbook.oauth_client.source_types.manager import MANAGER, RequestKind
 from passbook.oauth_client.utils import user_get_or_create
 from passbook.oauth_client.views.core import OAuthCallback, OAuthRedirect
@@ -22,12 +20,11 @@ class FacebookOAuth2Callback(OAuthCallback):
     """Facebook OAuth2 Callback"""
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('name'),
+            'username': info.get('name'),
             'email': info.get('email', ''),
             'first_name': info.get('name'),
             'password': None,
         }
-        fb_user = user_get_or_create(user_model=user, **user_data)
+        fb_user = user_get_or_create(**user_data)
         return fb_user
diff --git a/passbook/oauth_client/source_types/github.py b/passbook/oauth_client/source_types/github.py
index 38c2bb288..fb75fe506 100644
--- a/passbook/oauth_client/source_types/github.py
+++ b/passbook/oauth_client/source_types/github.py
@@ -1,7 +1,5 @@
 """GitHub OAuth Views"""
 
-from django.contrib.auth import get_user_model
-
 from passbook.oauth_client.source_types.manager import MANAGER, RequestKind
 from passbook.oauth_client.utils import user_get_or_create
 from passbook.oauth_client.views.core import OAuthCallback
@@ -12,12 +10,11 @@ class GitHubOAuth2Callback(OAuthCallback):
     """GitHub OAuth2 Callback"""
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('login'),
+            'username': info.get('login'),
             'email': info.get('email', ''),
             'first_name': info.get('name'),
             'password': None,
         }
-        gh_user = user_get_or_create(user_model=user, **user_data)
+        gh_user = user_get_or_create(**user_data)
         return gh_user
diff --git a/passbook/oauth_client/source_types/google.py b/passbook/oauth_client/source_types/google.py
index c739c1156..e92731b2e 100644
--- a/passbook/oauth_client/source_types/google.py
+++ b/passbook/oauth_client/source_types/google.py
@@ -1,6 +1,4 @@
 """Google OAuth Views"""
-from django.contrib.auth import get_user_model
-
 from passbook.oauth_client.source_types.manager import MANAGER, RequestKind
 from passbook.oauth_client.utils import user_get_or_create
 from passbook.oauth_client.views.core import OAuthCallback, OAuthRedirect
@@ -21,12 +19,11 @@ class GoogleOAuth2Callback(OAuthCallback):
     """Google OAuth2 Callback"""
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('email'),
+            'username': info.get('email'),
             'email': info.get('email', ''),
             'first_name': info.get('name'),
             'password': None,
         }
-        google_user = user_get_or_create(user_model=user, **user_data)
+        google_user = user_get_or_create(**user_data)
         return google_user
diff --git a/passbook/oauth_client/source_types/reddit.py b/passbook/oauth_client/source_types/reddit.py
index dbdd8c375..87f175eb5 100644
--- a/passbook/oauth_client/source_types/reddit.py
+++ b/passbook/oauth_client/source_types/reddit.py
@@ -2,7 +2,6 @@
 import json
 from logging import getLogger
 
-from django.contrib.auth import get_user_model
 from requests.auth import HTTPBasicAuth
 from requests.exceptions import RequestException
 
@@ -59,12 +58,11 @@ class RedditOAuth2Callback(OAuthCallback):
     client_class = RedditOAuth2Client
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('name'),
+            'username': info.get('name'),
             'email': None,
             'first_name': info.get('name'),
             'password': None,
         }
-        reddit_user = user_get_or_create(user_model=user, **user_data)
+        reddit_user = user_get_or_create(**user_data)
         return reddit_user
diff --git a/passbook/oauth_client/source_types/supervisr.py b/passbook/oauth_client/source_types/supervisr.py
index 9272e40f7..a0e702502 100644
--- a/passbook/oauth_client/source_types/supervisr.py
+++ b/passbook/oauth_client/source_types/supervisr.py
@@ -3,7 +3,6 @@
 import json
 from logging import getLogger
 
-from django.contrib.auth import get_user_model
 from requests.exceptions import RequestException
 
 from passbook.oauth_client.clients import OAuth2Client
@@ -44,12 +43,11 @@ class SupervisrOAuthCallback(OAuthCallback):
         return info['pk']
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('username'),
+            'username': info.get('username'),
             'email': info.get('email', ''),
             'first_name': info.get('first_name'),
             'password': None,
         }
-        sv_user = user_get_or_create(user_model=user, **user_data)
+        sv_user = user_get_or_create(**user_data)
         return sv_user
diff --git a/passbook/oauth_client/source_types/twitter.py b/passbook/oauth_client/source_types/twitter.py
index 60a7d8b2c..449268e93 100644
--- a/passbook/oauth_client/source_types/twitter.py
+++ b/passbook/oauth_client/source_types/twitter.py
@@ -2,7 +2,6 @@
 
 from logging import getLogger
 
-from django.contrib.auth import get_user_model
 from requests.exceptions import RequestException
 
 from passbook.oauth_client.clients import OAuthClient
@@ -36,12 +35,11 @@ class TwitterOAuthCallback(OAuthCallback):
     client_class = TwitterOAuthClient
 
     def get_or_create_user(self, source, access, info):
-        user = get_user_model()
         user_data = {
-            user.USERNAME_FIELD: info.get('screen_name'),
+            'username': info.get('screen_name'),
             'email': info.get('email', ''),
             'first_name': info.get('name'),
             'password': None,
         }
-        tw_user = user_get_or_create(user_model=user, **user_data)
+        tw_user = user_get_or_create(**user_data)
         return tw_user
diff --git a/passbook/oauth_client/utils.py b/passbook/oauth_client/utils.py
index 91ab2211b..ed5bd3e0e 100644
--- a/passbook/oauth_client/utils.py
+++ b/passbook/oauth_client/utils.py
@@ -1,16 +1,17 @@
 """OAuth Client User Creation Utils"""
 
-from django.contrib.auth import get_user_model
 from django.db.utils import IntegrityError
 
+from passbook.core.models import User
 
-def user_get_or_create(user_model=None, **kwargs):
+
+def user_get_or_create(**kwargs):
     """Create user or return existing user"""
-    if user_model is None:
-        user_model = get_user_model()
     try:
-        new_user = user_model.objects.create_user(**kwargs)
+        new_user = User.objects.create_user(**kwargs)
     except IntegrityError:
-        # TODO: Fix potential username change vuln
-        new_user = user_model.objects.get(username=kwargs['username'])
+        # At this point we've already checked that there is no existing connection
+        # to any user. Hence if we can't create the user,
+        kwargs['username'] = '%s_1' % kwargs['username']
+        new_user = User.objects.create_user(**kwargs)
     return new_user
diff --git a/passbook/oauth_client/views/core.py b/passbook/oauth_client/views/core.py
index fb5819b33..cb5af5102 100644
--- a/passbook/oauth_client/views/core.py
+++ b/passbook/oauth_client/views/core.py
@@ -113,7 +113,9 @@ class OAuthCallback(OAuthClientMixin, View):
                 )
             user = authenticate(source=self.source, identifier=identifier, request=request)
             if user is None:
+                LOGGER.debug("Handling new user")
                 return self.handle_new_user(self.source, connection, info)
+            LOGGER.debug("Handling existing user")
             return self.handle_existing_user(self.source, user, connection, info)
 
     # pylint: disable=unused-argument