diff --git a/gitlab/base.py b/gitlab/base.py
index 40bc06ce4..ad3533913 100644
--- a/gitlab/base.py
+++ b/gitlab/base.py
@@ -131,7 +131,7 @@ def _create_managers(self):
 
     def _update_attrs(self, new_attrs):
         self.__dict__["_updated_attrs"] = {}
-        self.__dict__["_attrs"].update(new_attrs)
+        self.__dict__["_attrs"] = new_attrs
 
     def get_id(self):
         """Returns the id of the resource."""
diff --git a/gitlab/tests/test_base.py b/gitlab/tests/test_base.py
index 58c0d4748..a0adcb03d 100644
--- a/gitlab/tests/test_base.py
+++ b/gitlab/tests/test_base.py
@@ -128,6 +128,13 @@ def test_update_attrs(self, fake_manager):
         assert {"foo": "foo", "bar": "bar"} == obj._attrs
         assert {} == obj._updated_attrs
 
+    def test_update_attrs_deleted(self, fake_manager):
+        obj = FakeObject(fake_manager, {"foo": "foo", "bar": "bar"})
+        obj.bar = "baz"
+        obj._update_attrs({"foo": "foo"})
+        assert {"foo": "foo"} == obj._attrs
+        assert {} == obj._updated_attrs
+
     def test_create_managers(self, fake_gitlab, fake_manager):
         class ObjectWithManager(FakeObject):
             _managers = (("fakes", "FakeManager"),)