diff --git a/src/xpdev/threadwrap.h b/src/xpdev/threadwrap.h
index a98c9f0809be60e1656aae8a54d644881e502492..97f8b8d256c2dc49ad1d0ffc890612894479e445 100644
--- a/src/xpdev/threadwrap.h
+++ b/src/xpdev/threadwrap.h
@@ -47,6 +47,7 @@ extern "C" {
 
 #if defined(__unix__)
 
+	#include <sys/param.h>
 	#include <pthread.h>	/* POSIX threads and mutexes */
 #if defined(_NEED_SEM)
 	#include "sem.h"