diff --git a/citadel/README.md b/citadel/README.md
index 1f0552b..1966da0 100644
--- a/citadel/README.md
+++ b/citadel/README.md
@@ -5,6 +5,10 @@ to provide advanced search functionality using an Elasticsearch backend.
 
 ## Changelog
 
+### 3.1
+
+- Correctly handle remote groups whose capitalization changed at some point
+
 ### 3.0
 
 - Initial release
diff --git a/citadel/indico_citadel/util.py b/citadel/indico_citadel/util.py
index 990fe48..01b5293 100644
--- a/citadel/indico_citadel/util.py
+++ b/citadel/indico_citadel/util.py
@@ -8,11 +8,14 @@
 import re
 import sys
 import threading
+from collections import defaultdict
 from functools import wraps
 
 from flask import current_app
 from flask.globals import _app_ctx_stack
 
+from indico.core.db import db
+from indico.core.db.sqlalchemy.principals import PrincipalMixin, PrincipalPermissionsMixin, PrincipalType
 from indico.modules.groups import GroupProxy
 from indico.util.caching import memoize_redis
 
@@ -174,6 +177,31 @@ def _flatten(obj, target_key='buckets', parent_key=''):
         yield from _flatten(value, target_key, f'{parent_key}_{key}' if parent_key else key)
 
 
+@memoize_redis(86400)
+def _get_alternative_group_names():
+    """Get non-lowercase versions of group names."""
+    classes = [sc for sc in [*PrincipalMixin.__subclasses__(), *PrincipalPermissionsMixin.__subclasses__()]
+               if hasattr(sc, 'query')]
+    alternatives = defaultdict(set)
+    for cls in classes:
+        res = (db.session.query(cls.multipass_group_provider, cls.multipass_group_name)
+               .distinct()
+               .filter(cls.type == PrincipalType.multipass_group,
+                       cls.multipass_group_name != db.func.lower(cls.multipass_group_name))
+               .all())
+        for provider, name in res:
+            alternatives[(provider, name.lower())].add(name)
+    return dict(alternatives)
+
+
+def _include_capitalized_groups(groups):
+    alternatives = _get_alternative_group_names()
+    for group in groups:
+        yield group.identifier
+        for alt_name in alternatives.get((group.provider, group.name.lower()), ()):
+            yield GroupProxy(alt_name, group.provider).identifier
+
+
 @memoize_redis(3600)
 def get_user_access(user, admin_override_enabled=False):
     if not user:
@@ -183,6 +211,7 @@ def get_user_access(user, admin_override_enabled=False):
     access = [user.identifier] + [u.identifier for u in user.get_merged_from_users_recursive()]
     access += [GroupProxy(x.id, _group=x).identifier for x in user.local_groups]
     if user.can_get_all_multipass_groups:
-        access += [GroupProxy(x.name, x.provider.name, x).identifier
-                   for x in user.iter_all_multipass_groups()]
+        multipass_groups = [GroupProxy(x.name, x.provider.name, x)
+                            for x in user.iter_all_multipass_groups()]
+        access += _include_capitalized_groups(multipass_groups)
     return access