diff --git a/chrome/browser/search/background/ntp_backgrounds.h b/chrome/browser/search/background/ntp_backgrounds.h
index 7afc0a230..6a6ad3b48 100644
--- a/chrome/browser/search/background/ntp_backgrounds.h
+++ b/chrome/browser/search/background/ntp_backgrounds.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_SEARCH_BACKGROUND_NTP_BACKGROUNDS_H_
 #define CHROME_BROWSER_SEARCH_BACKGROUND_NTP_BACKGROUNDS_H_
 
+#include <cstddef>
 #include <array>
 
 class GURL;