diff --git a/libretroshare/src/util/rstime.cc b/libretroshare/src/util/rstime.cc
index 74808afb9..067466d65 100644
--- a/libretroshare/src/util/rstime.cc
+++ b/libretroshare/src/util/rstime.cc
@@ -27,6 +27,7 @@
 #include <thread>
 #include <sys/time.h>
 #include <sys/unistd.h>
+#include <unistd.h>
 #include "rstime.h"
 
 namespace rstime {