diff --git a/Core/apu.h b/Core/apu.h
index df1be40..9d5fc80 100644
--- a/Core/apu.h
+++ b/Core/apu.h
@@ -124,7 +124,7 @@ typedef struct
     uint8_t channel_1_restart_hold;
     int8_t channel_4_delta;
     bool channel_4_countdown_reloaded;
-    
+    uint8_t channel_4_dmg_delayed_start;
 } GB_apu_t;
 
 typedef enum {