diff --git a/app/src/main/cpp/visualizer/execute_fft.c b/app/src/main/cpp/visualizer/execute_fft.c
index 4ef3491..6a4f821 100644
--- a/app/src/main/cpp/visualizer/execute_fft.c
+++ b/app/src/main/cpp/visualizer/execute_fft.c
@@ -44,7 +44,7 @@
     return VLC_SUCCESS;
 }
 
-/*static*/ block_t *filter_audio(filter_sys_t *p_sys, block_t *p_in_buf)
+/*static*/ block_t *filter_audio(filter_sys_t *p_sys, void *p_in_buf)
 {
     return vlc_queue_push(&p_sys->queue, p_in_buf);
 }
diff --git a/app/src/main/cpp/visualizer/execute_fft.h b/app/src/main/cpp/visualizer/execute_fft.h
index 400c8f7..6b8e6fc 100644
--- a/app/src/main/cpp/visualizer/execute_fft.h
+++ b/app/src/main/cpp/visualizer/execute_fft.h
@@ -41,7 +41,7 @@ static void *fft_thread(void *);
 
 /*static*/ int open_visualizer(filter_sys_t *p_sys);
 
-/*static*/ block_t *filter_audio(filter_sys_t *p_sys, block_t *p_in_buf);
+/*static*/ block_t *filter_audio(filter_sys_t *p_sys, void *p_in_buf);
 
 /*static*/ void close_visualizer(filter_sys_t *p_filter);