diff --git a/src/cpp11.cpp b/src/cpp11.cpp
index 54b85299..3526afa4 100644
--- a/src/cpp11.cpp
+++ b/src/cpp11.cpp
@@ -4,7 +4,6 @@
 #include "vroom_types.h"
 #include "cpp11/declarations.hpp"
 #include <R_ext/Visibility.h>
-#include <cstddef>
 
 // altrep.cc
 void force_materialization(SEXP x);