diff --git a/auth_token/include/proto.h b/auth_token/include/proto.h
index 68edb644..87b90eb1 100644
--- a/auth_token/include/proto.h
+++ b/auth_token/include/proto.h
@@ -63,6 +63,7 @@
 // 
 #define HTTP_OK_STATUS_CODE "200"
 #define HTTP_UNAUTHORIZED_STATUS_CODE "401"
+#define HTTP_NOT_FOUND_STATUS_CODE "404"
 #define HTTP_SERVER_ERROR_STATUS_CODE "500"