explicitly include <unistd.h> for close(2)
diff --git a/lib/pack_create.c b/lib/pack_create.c
index 273f38d..3cd0e26 100644
--- a/lib/pack_create.c
+++ b/lib/pack_create.c
@@ -30,6 +30,7 @@
#include <string.h>
#include <sha1.h>
#include <time.h>
+#include <unistd.h>
#include <limits.h>
#include <zlib.h>