diff --git a/homeassistant/components/google_assistant/trait.py b/homeassistant/components/google_assistant/trait.py
index b248ffbac22..3752574f31f 100644
--- a/homeassistant/components/google_assistant/trait.py
+++ b/homeassistant/components/google_assistant/trait.py
@@ -75,7 +75,6 @@ from homeassistant.util.percentage import (
 from homeassistant.util.unit_conversion import TemperatureConverter
 
 from .const import (
-    CHALLENGE_ACK_NEEDED,
     CHALLENGE_FAILED_PIN_NEEDED,
     CHALLENGE_PIN_NEEDED,
     ERR_ALREADY_ARMED,
@@ -2131,14 +2130,6 @@ def _verify_pin_challenge(data, state, challenge):
         raise ChallengeNeeded(CHALLENGE_FAILED_PIN_NEEDED)
 
 
-def _verify_ack_challenge(data, state, challenge):
-    """Verify an ack challenge."""
-    if not data.config.should_2fa(state):
-        return
-    if not challenge or not challenge.get("ack"):
-        raise ChallengeNeeded(CHALLENGE_ACK_NEEDED)
-
-
 MEDIA_COMMAND_SUPPORT_MAPPING = {
     COMMAND_MEDIA_NEXT: media_player.SUPPORT_NEXT_TRACK,
     COMMAND_MEDIA_PAUSE: media_player.SUPPORT_PAUSE,