diff --git a/src/butil/strings/string_piece.h b/src/butil/strings/string_piece.h
index c83e810556..933cefc965 100644
--- a/src/butil/strings/string_piece.h
+++ b/src/butil/strings/string_piece.h
@@ -165,6 +165,7 @@ template <typename STRING_TYPE> class BasicStringPiece {
   typedef size_t size_type;
   typedef typename STRING_TYPE::value_type value_type;
   typedef const value_type* pointer;
+  typedef const value_type* const_pointer;
   typedef const value_type& reference;
   typedef const value_type& const_reference;
   typedef ptrdiff_t difference_type;