diff --git a/src/fenrir-package/sound/sox.py b/src/fenrir-package/sound/sox.py
index b1aa8ff8..17bc0b84 100644
--- a/src/fenrir-package/sound/sox.py
+++ b/src/fenrir-package/sound/sox.py
@@ -7,5 +7,7 @@ class sound():
         pass
     def playSoundFile(self, Path):
         pass
+    def setCallback(self, callback)
+        pass
     def shutdown(self):
         pass