diff --git a/homeassistant/components/twentemilieu/__init__.py b/homeassistant/components/twentemilieu/__init__.py
index b6728b96536..0a2fb50c7c4 100644
--- a/homeassistant/components/twentemilieu/__init__.py
+++ b/homeassistant/components/twentemilieu/__init__.py
@@ -49,12 +49,6 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     )
     await coordinator.async_config_entry_first_refresh()
 
-    # For backwards compat, set unique ID
-    if entry.unique_id is None:
-        hass.config_entries.async_update_entry(
-            entry, unique_id=str(entry.data[CONF_ID])
-        )
-
     entry.runtime_data = coordinator
     await hass.config_entries.async_forward_entry_setups(entry, PLATFORMS)
 
diff --git a/tests/components/twentemilieu/test_init.py b/tests/components/twentemilieu/test_init.py
index d4c519d6f66..7e08b5f4938 100644
--- a/tests/components/twentemilieu/test_init.py
+++ b/tests/components/twentemilieu/test_init.py
@@ -44,18 +44,3 @@ async def test_config_entry_not_ready(
 
     assert mock_request.call_count == 1
     assert mock_config_entry.state is ConfigEntryState.SETUP_RETRY
-
-
-@pytest.mark.usefixtures("mock_twentemilieu")
-async def test_update_config_entry_unique_id(
-    hass: HomeAssistant,
-    mock_config_entry: MockConfigEntry,
-) -> None:
-    """Test the we update old config entries with an unique ID."""
-    mock_config_entry.add_to_hass(hass)
-    hass.config_entries.async_update_entry(mock_config_entry, unique_id=None)
-
-    await hass.config_entries.async_setup(mock_config_entry.entry_id)
-    await hass.async_block_till_done()
-
-    assert mock_config_entry.unique_id == "12345"