diff --git a/src/rendering/r_sky.h b/src/rendering/r_sky.h
index 47f563e6e..5d7236dc8 100644
--- a/src/rendering/r_sky.h
+++ b/src/rendering/r_sky.h
@@ -29,6 +29,7 @@
 #define __R_SKY_H__
 
 #include <utility>
+#include <stdint.h>
 #include "textureid.h"
 
 struct FLevelLocals;