diff --git a/tests/components/voip/test_voip.py b/tests/components/voip/test_voip.py
index 364c4d3dd5a..db3bafb2fcc 100644
--- a/tests/components/voip/test_voip.py
+++ b/tests/components/voip/test_voip.py
@@ -115,7 +115,8 @@ async def test_calls_not_allowed(
 
         # Should be problem.pcm from components/voip
         played_audio_bytes = audio_bytes
-        done.set()
+        # Use call_soon_threadsafe because send_audio runs in an executor thread
+        hass.loop.call_soon_threadsafe(done.set)
 
     protocol.transport = Mock()
     protocol.loop_delay = 0