diff --git a/platypush/plugins/sound/core.py b/platypush/plugins/sound/core.py
index 613a6b2f7..ef72028ea 100644
--- a/platypush/plugins/sound/core.py
+++ b/platypush/plugins/sound/core.py
@@ -199,6 +199,8 @@ class Mix(object):
             is set. Possible values: "``scale``" (scale down the frame to remove
             the clipping) or "``clip``" (saturate the values above/below range).
             Default: "``scale``".
+        :type on_clip: str
+
         :param samplerate: Audio sample rate. Default: 44100 Hz
         :type samplerate: int