diff --git a/source/PixelFormats.h b/source/PixelFormats.h
index e2a933a..7c5068a 100644
--- a/source/PixelFormats.h
+++ b/source/PixelFormats.h
@@ -28,6 +28,8 @@
 #ifndef HapCodec_PixelFormats_h
 #define HapCodec_PixelFormats_h
 
+#include <MacTypes.h>
+
 /*
  S3TC RGB DXT1
  */