diff --git a/gluon/tests/test_tools.py b/gluon/tests/test_tools.py
index fa963144..91a9de6d 100644
--- a/gluon/tests/test_tools.py
+++ b/gluon/tests/test_tools.py
@@ -870,13 +870,62 @@ class TestAuth(unittest.TestCase):
         count_log_event_test_after = self.db(self.db.auth_event.id > 0).count()
         self.assertEqual(count_log_event_test_after, count_log_event_test_before)
 
-    # Waiting guidance : https://github.com/web2py/web2py/issues/1300
-    # def test_add_membership(self):
-    #     self.auth.login_user(self.db(self.db.auth_user.username == 'bart').select().first())  # bypass login_bare()
-    #     # failing case
-    #     rtn = self.auth.add_membership('not_existing_role_name')
-    #     # self.assertEqual(rtn, 'test')
-    #     self.assertEqual(self.db(self.db.auth_group.role == 'not_existing_role_name').select().first(), 'test')
+    def test_add_membership(self):
+        user = self.db(self.db.auth_user.username == 'bart').select().first() # bypass login_bare()
+        user_id = user.id
+        role_name = 'test_add_membership_group'
+        group_id = self.auth.add_group(role_name)
+        self.assertFalse(self.auth.has_membership(role_name))
+
+        self.auth.add_membership(group_id=group_id, user_id=user_id)
+        self.assertTrue(self.auth.has_membership(group_id, user_id=user_id))
+        self.auth.del_membership(group_id=group_id, user_id=user_id)
+        self.assertFalse(self.auth.has_membership(group_id, user_id=user_id))
+
+        self.auth.add_membership(role=role_name, user_id=user_id)
+        self.assertTrue(self.auth.has_membership(group_id, user_id=user_id))
+        self.auth.del_membership(group_id=group_id, user_id=user_id)
+        self.assertFalse(self.auth.has_membership(group_id, user_id=user_id))
+
+        with self.myassertRaisesRegex(ValueError, '^group_id not provided or invalid$'):
+            self.auth.add_membership(group_id='not_existing_group_name', user_id=user_id)
+        with self.myassertRaisesRegex(ValueError, '^group_id not provided or invalid$'):
+            self.auth.add_membership(role='not_existing_role_name', user_id=user_id)
+        with self.myassertRaisesRegex(ValueError, '^user_id not provided or invalid$'):
+            self.auth.add_membership(group_id=group_id, user_id=None)
+        with self.myassertRaisesRegex(ValueError, '^user_id not provided or invalid$'):
+            self.auth.add_membership(role=role_name, user_id=None)
+
+        self.auth.login_user(user)
+
+        self.auth.add_membership(group_id=group_id)
+        self.assertTrue(self.auth.has_membership(group_id))
+        self.auth.del_membership(group_id=group_id)
+        self.assertFalse(self.auth.has_membership(group_id))
+
+        self.auth.add_membership(role=role_name)
+        self.assertTrue(self.auth.has_membership(group_id))
+        self.auth.del_membership(group_id=group_id)
+        self.assertFalse(self.auth.has_membership(group_id))
+
+        # default usage (group_id=role_name)
+        self.auth.add_membership(role_name)
+        self.assertTrue(self.auth.has_membership(group_id))
+        self.auth.del_membership(group_id=group_id)
+        self.assertFalse(self.auth.has_membership(group_id))
+
+        # re-adding a membership should return the existing membership
+        record0_id = self.auth.add_membership(group_id)
+        self.assertTrue(self.auth.has_membership(group_id))
+        record1_id = self.auth.add_membership(group_id)
+        self.assertEqual(record0_id, record1_id)
+        self.auth.del_membership(group_id=group_id)
+        self.assertFalse(self.auth.has_membership(group_id))
+
+        with self.myassertRaisesRegex(ValueError, '^group_id not provided or invalid$'):
+            self.auth.add_membership(group_id='not_existing_group_name')
+        with self.myassertRaisesRegex(ValueError, '^group_id not provided or invalid$'):
+            self.auth.add_membership(role='not_existing_role_name')
 
     def test_del_membership(self):
         self.auth.login_user(self.db(self.db.auth_user.username == 'bart').select().first())  # bypass login_bare()
diff --git a/gluon/tools.py b/gluon/tools.py
index f88a01bc..e0838f9f 100644
--- a/gluon/tools.py
+++ b/gluon/tools.py
@@ -4439,6 +4439,10 @@ class Auth(object):
             group_id = self.id_group(group_id)  # interpret group_id as a role
         if not user_id and self.user:
             user_id = self.user.id
+        if not group_id:
+            raise ValueError('group_id not provided or invalid')
+        if not user_id:
+            raise ValueError('user_id not provided or invalid')
         membership = self.table_membership()
         db = membership._db
         record = db((membership.user_id == user_id) &