diff --git a/module_usb_audio/usb_buffer/decouple.xc b/module_usb_audio/usb_buffer/decouple.xc
index a49e016e..54aaefe2 100644
--- a/module_usb_audio/usb_buffer/decouple.xc
+++ b/module_usb_audio/usb_buffer/decouple.xc
@@ -200,6 +200,7 @@ __builtin_unreachable();
                 {
 #pragma xta endpoint "mixer_request"
                     int sample;
+                    int mult;
                     int h;
                     unsigned l;