diff --git a/backend/package.json b/backend/package.json
index 3a86999..8e73beb 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sub-store",
-  "version": "2.13.4",
+  "version": "2.13.5",
   "description": "Advanced Subscription Manager for QX, Loon, Surge, Stash and ShadowRocket.",
   "main": "src/main.js",
   "scripts": {
diff --git a/backend/src/restful/subscriptions.js b/backend/src/restful/subscriptions.js
index aeb184e..e192111 100644
--- a/backend/src/restful/subscriptions.js
+++ b/backend/src/restful/subscriptions.js
@@ -66,8 +66,12 @@ async function getFlowInfo(req, res) {
         }
 
         // unit is KB
-        const upload = Number(flowHeaders.match(/upload=(\d+)/)[1]);
-        const download = Number(flowHeaders.match(/download=(\d+)/)[1]);
+        const uploadMatch = flowHeaders.match(/upload=(-?)(\d+)/)
+        const upload = Number(uploadMatch[1] + uploadMatch[2]);
+
+        const downloadMatch = flowHeaders.match(/download=(-?)(\d+)/)
+        const download = Number(downloadMatch[1] + downloadMatch[2]);
+
         const total = Number(flowHeaders.match(/total=(\d+)/)[1]);
 
         // optional expire timestamp