diff --git a/app/__init__.py b/app/__init__.py
index dbbe1b081..9614d55b3 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -228,7 +228,9 @@ class ReverseProxied(object):
 
 def create_app(config_class=DevConfig):
     app = Flask(__name__, static_url_path="/ScoDoc/static", static_folder="static")
-    CAS(app, url_prefix="/cas")
+    from app.auth import cas
+
+    CAS(app, url_prefix="/cas", configuration_function=cas.set_cas_configuration)
     app.wsgi_app = ReverseProxied(app.wsgi_app)
     app.json_encoder = ScoDocJSONEncoder
 
diff --git a/app/auth/cas.py b/app/auth/cas.py
index 2a037744a..469617298 100644
--- a/app/auth/cas.py
+++ b/app/auth/cas.py
@@ -42,7 +42,9 @@ def after_cas_login():
                     )
             else:
                 current_app.logger.info(
-                    f"""CAS login denied for {user.user_name if user else ""} cas_id={cas_id} (unknown or inactive)"""
+                    f"""CAS login denied for {
+                        user.user_name if user else ""
+                    } cas_id={cas_id} (unknown or inactive)"""
                 )
         else:
             current_app.logger.info(
@@ -75,6 +77,7 @@ def set_cas_configuration(app: flask.app.Flask = None):
     """
     app = app or current_app
     if ScoDocSiteConfig.is_cas_enabled():
+        current_app.logger.info("CAS: set_cas_configuration")
         app.config["CAS_SERVER"] = ScoDocSiteConfig.get("cas_server")
         app.config["CAS_AFTER_LOGIN"] = "auth.after_cas_login"
         app.config["CAS_AFTER_LOGOUT"] = "auth.after_cas_logout"
diff --git a/flask_cas/__init__.py b/flask_cas/__init__.py
index 76e02c252..eae421391 100644
--- a/flask_cas/__init__.py
+++ b/flask_cas/__init__.py
@@ -17,6 +17,7 @@ from . import routing
 
 from functools import wraps
 
+
 class CAS(object):
     """
     Required Configs:
@@ -39,68 +40,69 @@ class CAS(object):
     |CAS_AFTER_LOGOUT           | None                  |
     """
 
-    def __init__(self, app=None, url_prefix=None):
+    def __init__(self, app=None, url_prefix=None, configuration_function=None):
         self._app = app
         if app is not None:
-            self.init_app(app, url_prefix)
+            self.init_app(app, url_prefix, configuration_function)
 
-    def init_app(self, app, url_prefix=None):
+    def init_app(self, app, url_prefix=None, configuration_function=None):
         # Configuration defaults
-        app.config.setdefault('CAS_TOKEN_SESSION_KEY', '_CAS_TOKEN')
-        app.config.setdefault('CAS_USERNAME_SESSION_KEY', 'CAS_USERNAME')
-        app.config.setdefault('CAS_ATTRIBUTES_SESSION_KEY', 'CAS_ATTRIBUTES')
-        app.config.setdefault('CAS_LOGIN_ROUTE', '/cas')
-        app.config.setdefault('CAS_LOGOUT_ROUTE', '/cas/logout')
-        app.config.setdefault('CAS_VALIDATE_ROUTE', '/cas/serviceValidate')
+        app.config.setdefault("CAS_TOKEN_SESSION_KEY", "_CAS_TOKEN")
+        app.config.setdefault("CAS_USERNAME_SESSION_KEY", "CAS_USERNAME")
+        app.config.setdefault("CAS_ATTRIBUTES_SESSION_KEY", "CAS_ATTRIBUTES")
+        app.config.setdefault("CAS_LOGIN_ROUTE", "/cas")
+        app.config.setdefault("CAS_LOGOUT_ROUTE", "/cas/logout")
+        app.config.setdefault("CAS_VALIDATE_ROUTE", "/cas/serviceValidate")
+        app.config.setdefault("CAS_CONFIGURATION_FUNCTION", configuration_function)
         # Requires CAS 2.0
-        app.config.setdefault('CAS_AFTER_LOGOUT', None)
+        app.config.setdefault("CAS_AFTER_LOGOUT", None)
         # Register Blueprint
         app.register_blueprint(routing.blueprint, url_prefix=url_prefix)
 
         # Use the newstyle teardown_appcontext if it's available,
         # otherwise fall back to the request context
-        if hasattr(app, 'teardown_appcontext'):
+        if hasattr(app, "teardown_appcontext"):
             app.teardown_appcontext(self.teardown)
         else:
             app.teardown_request(self.teardown)
 
     def teardown(self, exception):
         ctx = stack.top
-    
+
     @property
     def app(self):
         return self._app or current_app
 
     @property
     def username(self):
-        return flask.session.get(
-            self.app.config['CAS_USERNAME_SESSION_KEY'], None)
+        return flask.session.get(self.app.config["CAS_USERNAME_SESSION_KEY"], None)
 
     @property
     def attributes(self):
-        return flask.session.get(
-            self.app.config['CAS_ATTRIBUTES_SESSION_KEY'], None)
+        return flask.session.get(self.app.config["CAS_ATTRIBUTES_SESSION_KEY"], None)
 
     @property
     def token(self):
-        return flask.session.get(
-            self.app.config['CAS_TOKEN_SESSION_KEY'], None)
+        return flask.session.get(self.app.config["CAS_TOKEN_SESSION_KEY"], None)
+
 
 def login():
-    return flask.redirect(flask.url_for('cas.login', _external=True))
+    return flask.redirect(flask.url_for("cas.login", _external=True))
+
 
 def logout():
-    return flask.redirect(flask.url_for('cas.logout', _external=True))
+    return flask.redirect(flask.url_for("cas.logout", _external=True))
+
 
 def login_required(function):
     @wraps(function)
     def wrap(*args, **kwargs):
-        if 'CAS_USERNAME' not in flask.session:
-            flask.session['CAS_AFTER_LOGIN_SESSION_URL'] = (
-                flask.request.script_root +
-                flask.request.full_path
+        if "CAS_USERNAME" not in flask.session:
+            flask.session["CAS_AFTER_LOGIN_SESSION_URL"] = (
+                flask.request.script_root + flask.request.full_path
             )
             return login()
         else:
             return function(*args, **kwargs)
+
     return wrap
diff --git a/flask_cas/routing.py b/flask_cas/routing.py
index fbc880959..689530e71 100644
--- a/flask_cas/routing.py
+++ b/flask_cas/routing.py
@@ -32,6 +32,9 @@ def login():
     the user's attributes are saved under the key
     'CAS_USERNAME_ATTRIBUTE_KEY'
     """
+    conf_func = current_app.config.get("CAS_CONFIGURATION_FUNCTION")
+    if conf_func:  # call function setting app configuration
+        conf_func(current_app)
     if not "CAS_SERVER" in current_app.config:
         current_app.logger.info("cas_login: no configuration")
         return "CAS configuration missing"
@@ -72,7 +75,9 @@ def logout():
     """
     When the user accesses this route they are logged out.
     """
-
+    conf_func = current_app.config.get("CAS_CONFIGURATION_FUNCTION")
+    if conf_func:  # call function setting app configuration
+        conf_func(current_app)
     cas_username_session_key = current_app.config["CAS_USERNAME_SESSION_KEY"]
     cas_attributes_session_key = current_app.config["CAS_ATTRIBUTES_SESSION_KEY"]
     cas_token_session_key = current_app.config["CAS_TOKEN_SESSION_KEY"]
diff --git a/sco_version.py b/sco_version.py
index 53ca17870..46167352f 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.4.55"
+SCOVERSION = "9.4.56"
 
 SCONAME = "ScoDoc"