diff --git a/src/sound/allegro_s.cpp b/src/sound/allegro_s.cpp
index 3ce16b5c01..977f33bc87 100644
--- a/src/sound/allegro_s.cpp
+++ b/src/sound/allegro_s.cpp
@@ -9,6 +9,7 @@
 #include "../driver.h"
 #include "../mixer.h"
 #include "../sdl.h"
+#include "../debug.h"
 #include "allegro_s.h"
 #include <allegro.h>