Index: hplip-3.20.9/scan/sane/http.c
===================================================================
--- hplip-3.20.9.orig/scan/sane/http.c
+++ hplip-3.20.9/scan/sane/http.c
@@ -33,6 +33,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
 #include <syslog.h>
 #include <ctype.h>