diff --git a/apps/tdspeed.h b/apps/tdspeed.h
index 72acebebf8..bf20c15935 100644
--- a/apps/tdspeed.h
+++ b/apps/tdspeed.h
@@ -25,7 +25,7 @@
 
 #define TDSPEED_OUTBUFSIZE 4096
 
-void tdspeed_init();
+void tdspeed_init(void);
 bool tdspeed_config(int samplerate, bool stereo, int factor);
 long tdspeed_est_output_size(void);
 long tdspeed_est_input_size(long size);