diff --git a/src/audio_output.cpp b/src/audio_output.cpp
index 0b96caa..2b0b122 100644
--- a/src/audio_output.cpp
+++ b/src/audio_output.cpp
@@ -34,6 +34,7 @@
 #include "msg.h"
 #include "timer.h"
 #include "dbg.h"
+#include "AL/alext.h"
 
 
 /* This code is adapted from the alffmpeg.c example available here: