diff --git a/examples/utility.c b/examples/utility.c
index ef6ee10ce12c08c53e4b6468aeac99225c09e65b..a43f2b02b6b0acd6a91eb4d8fb60219658e46230 100644
--- a/examples/utility.c
+++ b/examples/utility.c
@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <string.h>
+#include <unistd.h>
 
 // allocates a buffer!
 char * buffer_pdl(char * filename) {