diff --git a/pipe.c b/pipe.c
--- a/pipe.c
+++ b/pipe.c
@@ -7,7 +7,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <wait.h>
+#include <sys/wait.h>
 #include <assert.h>
 
 #define MAX 50