diff --git a/custom_components/edge_tts/tts.py b/custom_components/edge_tts/tts.py
index a5565a8..c44f11d 100644
--- a/custom_components/edge_tts/tts.py
+++ b/custom_components/edge_tts/tts.py
@@ -400,7 +400,7 @@ async def async_get_tts_audio(self, message, language, options=None):
         tts = EdgeCommunicate(
             message,
             voice=voice,
-            pitch=opt.get('pitch', '+0%'),
+            pitch=opt.get('pitch', '+0Hz'),
             rate=opt.get('rate', '+0%'),
             volume=opt.get('volume', '+0%'),
         )