diff --git a/module_usb_audio/main.xc b/module_usb_audio/main.xc
index b79123ed..5d06954c 100755
--- a/module_usb_audio/main.xc
+++ b/module_usb_audio/main.xc
@@ -678,7 +678,11 @@ int main()
 
 #if (NUM_PDM_MICS > 0)
         on stdcore[PDM_TILE]: pdm_mic(c_ds_output);
+#ifdef MIC_PROCESSING_USE_INTERFACE
         on stdcore[PDM_TILE].core[0]: pdm_buffer(c_ds_output, c_pdm_pcm, i_mic_process);
+#else
+        on stdcore[PDM_TILE]: pdm_buffer(c_ds_output, c_pdm_pcm);
+#endif
 #endif
 
         USER_MAIN_CORES
diff --git a/module_usb_audio/pdm_mics/pdm_mic.xc b/module_usb_audio/pdm_mics/pdm_mic.xc
index 9c76235b..fa0d54de 100644
--- a/module_usb_audio/pdm_mics/pdm_mic.xc
+++ b/module_usb_audio/pdm_mics/pdm_mic.xc
@@ -29,12 +29,14 @@ int data_1[4*THIRD_STAGE_COEFS_PER_STAGE * MAX_DECIMATION_FACTOR] = {0};
 
 mic_array_frame_time_domain mic_audio[2];
 
-[[combinable]]
-void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio
 #ifdef MIC_PROCESSING_USE_INTERFACE
-   , client mic_process_if i_mic_process
+[[combinable]]
+#pragma unsafe arrays
+void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio, client mic_process_if i_mic_process)
+#else
+#pragma unsafe arrays
+void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio)
 #endif
-)
 {
     unsigned buffer;
     int output[NUM_PDM_MICS];
diff --git a/module_usb_audio/pdm_mics/xua_pdm_mic.h b/module_usb_audio/pdm_mics/xua_pdm_mic.h
index cf6f0e6d..69e52d5c 100644
--- a/module_usb_audio/pdm_mics/xua_pdm_mic.h
+++ b/module_usb_audio/pdm_mics/xua_pdm_mic.h
@@ -26,10 +26,13 @@ void pdm_mic(streaming chanend c_ds_output[2]);
 #else
 
 /* Simple user hooks/call-backs */
-unsafe void user_pdm_process(mic_array_frame_time_domain * unsafe audio, int output[]);
+void user_pdm_process(mic_array_frame_time_domain * unsafe audio, int output[]);
 
 void user_pdm_init();
 
+/* PDM interface and decimation cores */
+void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio);
+
 /* PDM interface and decimation cores */
 void pdm_mic(streaming chanend c_ds_output[2]);