diff --git a/test/unittests/test_speech.py b/test/unittests/test_speech.py
index 0e84e58..3257752 100644
--- a/test/unittests/test_speech.py
+++ b/test/unittests/test_speech.py
@@ -149,6 +149,7 @@ def execute(*args, **kwargs):
 
         speech = PlaybackService(bus=bus)
         speech.tts = FailingTTS()
+        speech._tts_hash = "123failing"
 
         speech.execute_tts("hello", "123")
         self.assertTrue(speech.fallback_tts.execute.called)