diff --git a/lib/main.js b/lib/main.js
index f7ca378..9742cae 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -28,12 +28,14 @@ async function run() {
     core.debug(` Detected version ${pkg.version}`)
 
     if (!process.env.hasOwnProperty('INPUT_GITHUB_TOKEN') || process.env.INPUT_GITHUB_TOKEN.trim().length === 0) {
-      core.setFailed('Invalid or missing GITHUB_TOKEN.')
-      return
+      if (!process.env.hasOwnProperty('GITHUB_TOKEN')) {
+        core.setFailed('Invalid or missing GITHUB_TOKEN.')
+        return
+      }
     }
 
     // Check for existing tag
-    const git = new github.GitHub(process.env.INPUT_GITHUB_TOKEN)
+    const git = new github.GitHub(process.env.INPUT_GITHUB_TOKEN || process.env.GITHUB_TOKEN)
     const owner = process.env.GITHUB_ACTOR
     const repo = process.env.GITHUB_REPOSITORY.split('/').pop()