diff --git a/awx/main/fields.py b/awx/main/fields.py
index 5f1761277d..d63eb54002 100644
--- a/awx/main/fields.py
+++ b/awx/main/fields.py
@@ -193,8 +193,10 @@ def update_role_parentage_for_instance(instance):
     '''
     for implicit_role_field in getattr(instance.__class__, '__implicit_role_fields'):
         cur_role = getattr(instance, implicit_role_field.name)
+        original_parents = set(json.loads(cur_role.implicit_parents))
         new_parents = implicit_role_field._resolve_parent_roles(instance)
-        cur_role.parents.set(new_parents)
+        cur_role.parents.remove(*list(original_parents - new_parents))
+        cur_role.parents.add(*list(new_parents - original_parents))
         new_parents_list = list(new_parents)
         new_parents_list.sort()
         new_parents_json = json.dumps(new_parents_list)
diff --git a/awx/main/models/rbac.py b/awx/main/models/rbac.py
index ae8c5e8705..7ce8567e88 100644
--- a/awx/main/models/rbac.py
+++ b/awx/main/models/rbac.py
@@ -172,7 +172,7 @@ class Role(models.Model):
         elif accessor.__class__.__name__ == 'Team':
             return self.ancestors.filter(pk=accessor.member_role.id).exists()
         elif type(accessor) == Role:
-            return self.ancestors.filter(pk=accessor).exists()
+            return self.ancestors.filter(pk=accessor.pk).exists()
         else:
             accessor_type = ContentType.objects.get_for_model(accessor)
             roles = Role.objects.filter(content_type__pk=accessor_type.id,
diff --git a/awx/main/tests/functional/test_rbac_core.py b/awx/main/tests/functional/test_rbac_core.py
index bae3b61dc0..abec03da45 100644
--- a/awx/main/tests/functional/test_rbac_core.py
+++ b/awx/main/tests/functional/test_rbac_core.py
@@ -5,6 +5,7 @@ from awx.main.models import (
     Organization,
     Project,
 )
+from awx.main.fields import update_role_parentage_for_instance
 
 
 @pytest.mark.django_db
@@ -202,3 +203,11 @@ def test_auto_parenting():
     assert org1.admin_role.is_ancestor_of(prj2.admin_role) is False
     assert org2.admin_role.is_ancestor_of(prj1.admin_role)
     assert org2.admin_role.is_ancestor_of(prj2.admin_role)
+
+
+@pytest.mark.django_db
+def test_update_parents_keeps_teams(team, project):
+    project.update_role.parents.add(team.member_role)
+    assert team.member_role in project.update_role  # test prep sanity check
+    update_role_parentage_for_instance(project)
+    assert team.member_role in project.update_role  # actual assertion