---
 src/config/config.hpp |    2 ++
 1 file changed, 2 insertions(+)

--- a/src/config/config.hpp
+++ b/src/config/config.hpp
@@ -37,6 +37,8 @@
 #define MPICH_SKIP_MPICXX
 #endif
 
+#include <cstddef>
+
 #include "config-features.hpp"
 
 /** P3M: Default for offset of first mesh point from the origin (left