diff --git a/lib/index.js b/lib/index.js
index 40966e9..91aca3c 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -40,7 +40,9 @@ const parseUrl = (url, normalize = false) => {
     const GIT_RE = /((git@|http(s)?:\/\/)([\w\.@]+)(\/|:))(([\~,\w,\-,\_,\/]+)(.git){0,1}((\/){0,1}))/
 
     if (typeof url !== "string" || !url.trim()) {
-        throw new Error("Invalid url.")
+        const err = new Error("Invalid url.")
+        err.subject_url = url
+        throw err
     }
 
     if (normalize) {