diff --git a/README.md b/README.md
index 2c8b55a6..c6b5fd73 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Use this action in a workflow [triggered by a release](https://docs.github.com/e
 
 ## Inputs
 
-**GITHUB_TOKEN**
+**GITHUB_TOKEN** (optional)
 
 A GitHub access token with write access to your repo's issues, such as:
 
diff --git a/action.yml b/action.yml
index 02b52ab6..c51f7a03 100644
--- a/action.yml
+++ b/action.yml
@@ -8,7 +8,8 @@ inputs:
     description: |
       A GitHub personal access token with repo scope, such as
       secrets.GITHUB_TOKEN.
-    required: true
+    default: ${{ github.token }}
+    required: false
   comment-template:
     description: |
       Text template for the comment string.