diff --git a/src/Backends/Audio.h b/src/Backends/Audio.h
index d1d32773..5f1d10d2 100644
--- a/src/Backends/Audio.h
+++ b/src/Backends/Audio.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <stddef.h>
+
 #include "../WindowsWrapper.h"
 
 typedef struct AudioBackend_Sound AudioBackend_Sound;