--- a/src/dhry1.c
+++ b/src/dhry1.c
@@ -2,6 +2,7 @@
 #include <sys/time.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
 //#include <gio/gio.h>
 
 Rec_Pointer  	Ptr_Glob, Next_Ptr_Glob;