diff --git a/flask_social/core.py b/flask_social/core.py
index 748323c..c182d42 100644
--- a/flask_social/core.py
+++ b/flask_social/core.py
@@ -33,7 +33,7 @@
     'SOCIAL_CONNECT_DENY_VIEW': '/',
     'SOCIAL_POST_OAUTH_CONNECT_SESSION_KEY': 'post_oauth_connect_url',
     'SOCIAL_POST_OAUTH_LOGIN_SESSION_KEY': 'post_oauth_login_url',
-    'SOCIAL_APP_URL': 'http://localhost'
+    'SOCIAL_APP_URL': None,
 }
 
 
diff --git a/flask_social/utils.py b/flask_social/utils.py
index 45c0609..91af2c0 100644
--- a/flask_social/utils.py
+++ b/flask_social/utils.py
@@ -32,9 +32,10 @@ def get_authorize_callback(endpoint, provider_id):
 
     param: endpoint: Absolute path to append to the application's host
     """
+    url_root = current_app.config['SOCIAL_APP_URL'] or request.url_root[:-1]
     endpoint_prefix = config_value('BLUEPRINT_NAME')
     url = url_for(endpoint_prefix + '.' + endpoint, provider_id=provider_id)
-    return request.url_root[:-1] + url
+    return url_root + url
 
 
 def get_connection_values_from_oauth_response(provider, oauth_response):