diff --git a/simulation/metaserver.cpp b/simulation/metaserver.cpp
index 7f43526..863e2dd 100644
--- a/simulation/metaserver.cpp
+++ b/simulation/metaserver.cpp
@@ -20,6 +20,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netdb.h>
+#include <unistd.h>
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"