diff --git a/util/config/oauth.py b/util/config/oauth.py
index a58a8f69d..35b4b02fb 100644
--- a/util/config/oauth.py
+++ b/util/config/oauth.py
@@ -5,6 +5,7 @@ import time
 
 from cachetools import TTLCache
 from jwkest.jwk import KEYS
+from util.string import slash_join
 
 logger = logging.getLogger(__name__)
 
@@ -31,12 +32,6 @@ class OAuthConfig(object):
   def client_secret(self):
     return self.config.get('CLIENT_SECRET')
 
-  def _get_url(self, endpoint, *args):
-    for arg in args:
-      endpoint = urlparse.urljoin(endpoint, arg)
-
-    return endpoint
-
   def get_redirect_uri(self, app_config, redirect_suffix=''):
     return '%s://%s/oauth2/%s/callback%s' % (app_config['PREFERRED_URL_SCHEME'],
                                              app_config['SERVER_HOSTNAME'],
@@ -95,40 +90,34 @@ class GithubOAuthConfig(OAuthConfig):
     return [org.lower() for org in allowed]
 
   def get_public_url(self, suffix):
-    return urlparse.urljoin(self._endpoint(), suffix)
+    return slash_join(self._endpoint(), suffix)
 
   def _endpoint(self):
-    endpoint = self.config.get('GITHUB_ENDPOINT', 'https://github.com')
-    if not endpoint.endswith('/'):
-      endpoint = endpoint + '/'
-    return endpoint
+    return self.config.get('GITHUB_ENDPOINT', 'https://github.com')
 
   def is_enterprise(self):
     return self._endpoint().find('.github.com') < 0
 
   def authorize_endpoint(self):
-    return self._get_url(self._endpoint(), '/login/oauth/authorize')  + '?'
+    return slash_join(self._endpoint(), '/login/oauth/authorize')  + '?'
 
   def token_endpoint(self):
-    return self._get_url(self._endpoint(), '/login/oauth/access_token')
+    return slash_join(self._endpoint(), '/login/oauth/access_token')
 
   def _api_endpoint(self):
-    return self.config.get('API_ENDPOINT', self._get_url(self._endpoint(), '/api/v3/'))
+    return self.config.get('API_ENDPOINT', slash_join(self._endpoint(), '/api/v3/'))
 
   def api_endpoint(self):
     return self._api_endpoint()[0:-1]
 
   def user_endpoint(self):
-    api_endpoint = self._api_endpoint()
-    return self._get_url(api_endpoint, 'user')
+    return slash_join(self._api_endpoint(), 'user')
 
   def email_endpoint(self):
-    api_endpoint = self._api_endpoint()
-    return self._get_url(api_endpoint, 'user/emails')
+    return slash_join(self._api_endpoint(), 'user/emails')
 
   def orgs_endpoint(self):
-    api_endpoint = self._api_endpoint()
-    return self._get_url(api_endpoint, 'user/orgs')
+    return slash_join(self._api_endpoint(), 'user/orgs')
 
   def validate_client_id_and_secret(self, http_client, app_config):
     # First: Verify that the github endpoint is actually Github by checking for the
@@ -150,14 +139,13 @@ class GithubOAuthConfig(OAuthConfig):
     # password:
     #   - If the {client_id, client_secret} pair is invalid in some way, we get a 401 error.
     #   - If the pair is valid, then we get a 404 because the 'foo' token does not exists.
-    validate_endpoint = self._get_url(api_endpoint, 'applications/%s/tokens/foo' % self.client_id())
+    validate_endpoint = slash_join(api_endpoint, 'applications/%s/tokens/foo' % self.client_id())
     result = http_client.get(validate_endpoint, auth=(self.client_id(), self.client_secret()),
                              timeout=5)
     return result.status_code == 404
 
   def validate_organization(self, organization_id, http_client):
-    api_endpoint = self._api_endpoint()
-    org_endpoint = self._get_url(api_endpoint, 'orgs/%s' % organization_id.lower())
+    org_endpoint = slash_join(self._api_endpoint(), 'orgs/%s' % organization_id.lower())
 
     result = http_client.get(org_endpoint,
                              headers={'Accept': 'application/vnd.github.moondragon+json'},
@@ -221,25 +209,22 @@ class GitLabOAuthConfig(OAuthConfig):
     super(GitLabOAuthConfig, self).__init__(config, key_name)
 
   def _endpoint(self):
-    endpoint = self.config.get('GITLAB_ENDPOINT', 'https://gitlab.com')
-    if not endpoint.endswith('/'):
-      endpoint = endpoint + '/'
-    return endpoint
+    return self.config.get('GITLAB_ENDPOINT', 'https://gitlab.com')
 
   def api_endpoint(self):
     return self._endpoint()
 
   def get_public_url(self, suffix):
-    return urlparse.urljoin(self._endpoint(), suffix)
+    return slash_join(self._endpoint(), suffix)
 
   def service_name(self):
     return 'GitLab'
 
   def authorize_endpoint(self):
-    return self._get_url(self._endpoint(), '/oauth/authorize')
+    return slash_join(self._endpoint(), '/oauth/authorize')
 
   def token_endpoint(self):
-    return self._get_url(self._endpoint(), '/oauth/token')
+    return slash_join(self._endpoint(), '/oauth/token')
 
   def validate_client_id_and_secret(self, http_client, app_config):
     url = self.token_endpoint()