diff --git a/tests/test_snapshot.py b/tests/test_snapshot.py
index a4753943..fc754ad9 100644
--- a/tests/test_snapshot.py
+++ b/tests/test_snapshot.py
@@ -1380,3 +1380,27 @@ def test_system_uuid_motherboard(user: UserClient):
     snap2, _ = user.post(s, res=Snapshot, status=422)
     txt = "We have detected that a there is a device in your inventory"
     assert txt in snap2['message'][0]
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_bug_4028_components(user: UserClient):
+    """Tests when we have one computer and then we change the disk, then
+    the new disk need to have placeholder too."""
+    s = yaml2json('real-eee-1001pxd.snapshot.12')
+    snap1, _ = user.post(s, res=Snapshot)
+    dev1 = m.Device.query.filter_by(id=snap1['device']['id']).one()
+    components1 = [c for c in dev1.components]
+    for c in s['components']:
+        if c['type'] == 'HardDrive':
+            c['serialNumber'] = 'E2024242CV86MF'
+
+    s['uuid'] = str(uuid4())
+    snap2, _ = user.post(s, res=Snapshot)
+    dev2 = m.Device.query.filter_by(id=snap2['device']['id']).one()
+    components2 = [c for c in dev2.components]
+
+    # import pdb; pdb.set_trace()
+
+    assert '' not in [c.phid() for c in components1]
+    assert '' not in [c.phid() for c in components2]
\ No newline at end of file