diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 2e70d2c8c9..497eb1952e 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -1333,6 +1333,8 @@ class ProjectOptionsSerializer(BaseSerializer):
             scm_type = attrs.get('scm_type', u'') or u''
         if self.instance and not scm_type:
             valid_local_paths.append(self.instance.local_path)
+        if scm_type and self.instance.local_path != attrs.get('local_path'):
+            errors['local_path'] = _(f'Cannot change local_path for {scm_type}-based projects')
         if scm_type:
             attrs.pop('local_path', None)
         if 'local_path' in attrs and attrs['local_path'] not in valid_local_paths:
diff --git a/awx/main/tests/functional/api/test_project.py b/awx/main/tests/functional/api/test_project.py
index 09fed17c67..a31eb0804a 100644
--- a/awx/main/tests/functional/api/test_project.py
+++ b/awx/main/tests/functional/api/test_project.py
@@ -99,3 +99,12 @@ def test_changing_overwrite_behavior_okay_if_not_used(post, patch, organization,
         expect=200
     )
     assert Project.objects.get(pk=r1.data['id']).allow_override is False
+
+
+@pytest.mark.django_db
+def test_scm_project_local_path_invalid(get, patch, project, admin):
+    url = reverse('api:project_detail', kwargs={'pk': project.id})
+    resp = patch(url, {'local_path': '/foo/bar'}, user=admin, expect=400)
+    assert resp.data['local_path'] == [
+        'Cannot change local_path for git-based projects'
+    ]