diff --git a/base/check_op.h b/base/check_op.h
index 4816df4e8..0087dfe40 100644
--- a/base/check_op.h
+++ b/base/check_op.h
@@ -6,6 +6,7 @@
 #define BASE_CHECK_OP_H_
 
 #include <cstddef>
+#include <cstring>
 #include <type_traits>
 
 #include "base/check.h"