diff --git a/module_usb_audio/pdm_mics/pdm_mic.xc b/module_usb_audio/pdm_mics/pdm_mic.xc
index 1e9c2147..2e3d7b7c 100644
--- a/module_usb_audio/pdm_mics/pdm_mic.xc
+++ b/module_usb_audio/pdm_mics/pdm_mic.xc
@@ -124,7 +124,7 @@ void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio)
     /* Run user code */
     /* TODO ideally processing done inplace - it then doesn't matter if it is run or not */
 #ifdef MIC_PROCESSING_USE_INTERFACE
-    i_mic_process.transfer_buffers(current, output);
+    i_mic_process.transfer_buffers(current);
 #else
     user_pdm_process(current);
 #endif
@@ -152,7 +152,7 @@ void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio)
 
                     /* Run user code */
 #ifdef MIC_PROCESSING_USE_INTERFACE
-                    i_mic_process.transfer_buffers(current, output);
+                    i_mic_process.transfer_buffers(current);
 #else
                     user_pdm_process(current);
 #endif
@@ -175,7 +175,7 @@ void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio)
 
                     /* Run user code */
 #ifdef MIC_PROCESSING_USE_INTERFACE
-                    i_mic_process.transfer_buffers(current, output);
+                    i_mic_process.transfer_buffers(current);
 #else
                     user_pdm_process(current);
 #endif
diff --git a/module_usb_audio/pdm_mics/xua_pdm_mic.h b/module_usb_audio/pdm_mics/xua_pdm_mic.h
index 525122c5..e962c6bb 100644
--- a/module_usb_audio/pdm_mics/xua_pdm_mic.h
+++ b/module_usb_audio/pdm_mics/xua_pdm_mic.h
@@ -5,7 +5,7 @@
 /* Interface based user processing */
 typedef interface mic_process_if
 {
-    void transfer_buffers(mic_array_frame_time_domain * unsafe audio, int output[]);
+    void transfer_buffers(mic_array_frame_time_domain * unsafe audio);
     void init();
 } mic_process_if;