diff --git a/tests/components/xiaomi_miio/test_button.py b/tests/components/xiaomi_miio/test_button.py
index 8084a8a8fa0..995c5ae034c 100644
--- a/tests/components/xiaomi_miio/test_button.py
+++ b/tests/components/xiaomi_miio/test_button.py
@@ -52,6 +52,7 @@ async def test_vacuum_button_params(hass: HomeAssistant) -> None:
     assert state.state == "unknown"
 
 
+@pytest.mark.freeze_time("2023-06-28 00:00:00+00:00")
 async def test_vacuum_button_press(hass: HomeAssistant) -> None:
     """Test pressing a vacuum button."""
 
@@ -71,7 +72,7 @@ async def test_vacuum_button_press(hass: HomeAssistant) -> None:
 
     state = hass.states.get(f"{entity_id}_reset_side_brush")
     assert state
-    assert state.state[0:21] == pressed_at.isoformat()[0:21]  # drop millisecs
+    assert state.state == pressed_at.isoformat()
 
 
 async def setup_component(hass: HomeAssistant, entity_name: str) -> str: