diff --git a/media/base/subsample_entry.h b/media/base/subsample_entry.h
index 48f8ea7..1135a18 100644
--- ./media/base/subsample_entry.h
+++ ./media/base/subsample_entry.h
@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include <vector>
+#include <cstddef>
 
 #include "media/base/media_export.h"