diff --git a/filter/bs412.h b/filter/bs412.h
index 4b5caa6..1f835a5 100644
--- a/filter/bs412.h
+++ b/filter/bs412.h
@@ -25,5 +25,5 @@ typedef struct
 float dbr_to_deviation(float dbr);
 float deviation_to_dbr(float deviation);
 
-void init_bs412(BS412Compressor *mpx, float mpx_deviation, float target_power, float attack, float release, int sample_rate);
+void init_bs412(BS412Compressor *mpx, float mpx_deviation, float target_power, float attack, float release, float max, int sample_rate);
 float bs412_compress(BS412Compressor *mpx, float average);
\ No newline at end of file