diff --git a/luncho/blueprints/groups.py b/luncho/blueprints/groups.py
index e15f645..221fb3a 100644
--- a/luncho/blueprints/groups.py
+++ b/luncho/blueprints/groups.py
@@ -55,17 +55,14 @@ def create_group(token):
         return JSONError(412, 'Account not verified')
 
     json = request.get_json(force=True)
-    try:
-        new_group = Group(name=json['name'],
-                          owner=user.username)
+    new_group = Group(name=json['name'],
+                        owner=user.username)
 
-        LOG.debug('Current user groups: {groups}'.format(groups=user.groups))
-        user.groups.append(new_group)
+    LOG.debug('Current user groups: {groups}'.format(groups=user.groups))
+    user.groups.append(new_group)
 
-        db.session.add(new_group)
-        db.session.commit()
-    except IntegrityError:
-        return JSONError(500, 'Unknown error')
+    db.session.add(new_group)
+    db.session.commit()
 
     return jsonify(status='OK',
                    id=new_group.id)
diff --git a/luncho/server.py b/luncho/server.py
index 635d6bf..aba66e7 100644
--- a/luncho/server.py
+++ b/luncho/server.py
@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 # -*- encoding: utf-8 -*-
 
-import sys
 import logging
 import json
 import hmac
@@ -106,11 +105,3 @@ app.register_blueprint(index, url_prefix='/')
 app.register_blueprint(token, url_prefix='/token/')
 app.register_blueprint(users, url_prefix='/user/')
 app.register_blueprint(groups, url_prefix='/group/')
-
-
-# ----------------------------------------------------------------------
-#  Main
-# ----------------------------------------------------------------------
-if __name__ == '__main__':
-    log.warning('Use manage.py to run the server.')
-    sys.exit(1)
diff --git a/tests/group_tests.py b/tests/group_tests.py
index 8f2284b..2ec20a9 100644
--- a/tests/group_tests.py
+++ b/tests/group_tests.py
@@ -57,6 +57,35 @@ class TestGroups(LunchoTests):
                                        'name': 'Test group',
                                        'admin': True}])
 
+    def test_get_groups_unknown_token(self):
+        """Request groups with an unknown token."""
+        rv = self.get('/group/{token}/'.format(token='invalid'))
+        self.assertJsonError(rv, 404, 'User not found (via token)')
+
+    def test_get_groups_expired_token(self):
+        """Request groups with an expired token."""
+        self.user.token = 'expired'
+        server.db.session.commit()
+
+        rv = self.get('/group/{token}/'.format(token=self.user.token))
+        self.assertJsonError(rv, 400, 'Invalid token')
+
+    def test_create_group_unknown_token(self):
+        """Try to create a group with an invalid token."""
+        request = {'name': 'Test group'}
+        rv = self.put('/group/{token}/'.format(token='invalid'),
+                      request)
+        self.assertJsonError(rv, 404, 'User not found (via token)')
+
+    def test_create_group_expired_token(self):
+        self.user.token = 'expired'
+        server.db.session.commit()
+
+        request = {'name': 'Test group'}
+        rv = self.put('/group/{token}/'.format(token=self.user.token),
+                      request)
+        self.assertJsonError(rv, 400, 'Invalid token')
+
 
 class TestExistingGroups(LunchoTests):
     """Test for existing groups."""
@@ -92,6 +121,26 @@ class TestExistingGroups(LunchoTests):
         group = Group.query.get(groupId)
         self.assertEqual(group.name, request['name'])
 
+    def test_update_name_invalid_token(self):
+        """Try to change the name with an unknown token."""
+        groupId = self.group.id
+        request = {'name': 'New test group'}
+        rv = self.post('/group/{token}/{groupId}/'.format(token='invalid',
+                                                          groupId=self.group.id),
+                       request)
+        self.assertJsonError(rv, 404, 'User not found (via token)')
+
+    def test_update_name_expired_token(self):
+        """Try to change the name with an expired token."""
+        self.user.token = 'expired'
+        server.db.session.commit()
+
+        request = {'name': 'New test group'}
+        rv = self.post('/group/{token}/{groupId}/'.format(token=self.user.token,
+                                                          groupId=self.group.id),
+                       request)
+        self.assertJsonError(rv, 400, 'Invalid token')
+
     def test_update_owner(self):
         """Change the group owner."""
         new_user = User(username='another_user',
@@ -114,6 +163,18 @@ class TestExistingGroups(LunchoTests):
         group = Group.query.get(groupId)
         self.assertEqual(group.owner, new_username)
 
+    def test_update_owner_invalid(self):
+        """Try to change the owner to a user that doesn't exist."""
+        groupId = self.group.id
+        current_owner = self.group.owner
+
+        request = {'maintainer': 'unknown'}
+        rv = self.post('/group/{token}/{groupId}/'.format(
+            token=self.user.token,
+            groupId=self.group.id
+        ), request)
+        self.assertJsonError(rv, 401, 'New maintainer not found')
+
     def test_update_unknown_group(self):
         """Try to update a group that doesn't exist."""
         groupId = self.group.id + 10
@@ -154,5 +215,12 @@ class TestExistingGroups(LunchoTests):
             groupId=self.group.id))
         self.assertJsonError(rv, 401, 'User is not admin')
 
+    def test_delete_invalid_token(self):
+        """Try to delete a group with an unknown token."""
+        rv = self.delete('/group/{token}/{groupId}/'.format(
+            token='invalid',
+            groupId=self.group.id))
+        self.assertJsonError(rv, 404, 'User not found (via token)')
+
 if __name__ == '__main__':
     unittest.main()