diff --git a/tools/atree/files.cpp b/tools/atree/files.cpp
index 0f59521..c675ab7 100644
--- a/tools/atree/files.cpp
+++ b/tools/atree/files.cpp
@@ -1,5 +1,7 @@
 #include "files.h"
 #include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
 #include <errno.h>
 #include <sys/stat.h>
 #include <unistd.h>