Stop using TRUE and FALSE for exit status.
diff --git a/sleep.c b/sleep.c
index 709e3de..ad92b10 100644
--- a/sleep.c
+++ b/sleep.c
@@ -32,7 +32,7 @@
 
 	if (sleep(atoi(*(++argv))) != 0) {
 		perror("sleep");
-		exit(FALSE);
+		return EXIT_FAILURE;
 	}
-	return(TRUE);
+	return EXIT_SUCCESS;
 }