diff --git a/code/ryzom/client/src/stdpch.h b/code/ryzom/client/src/stdpch.h
index 45957ec35..fdb16ef93 100644
--- a/code/ryzom/client/src/stdpch.h
+++ b/code/ryzom/client/src/stdpch.h
@@ -16,6 +16,7 @@
 
 #include <nel/misc/types_nl.h>
 
+#include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <math.h>