diff --git a/index.js b/index.js
index 0437a4b..c234f1e 100644
--- a/index.js
+++ b/index.js
@@ -94,7 +94,7 @@ module.exports = app => {
     };
 
     // Max github body is 65536 characters... we are a little conservative.
-    report = report.substring(0, 65000)
+    report = report.substr(-65000)
 
     if (report.error) {
       app.log(`error: ${report.stderr}`)