diff --git a/README.md b/README.md
index 70ec620..c89e402 100644
--- a/README.md
+++ b/README.md
@@ -85,6 +85,7 @@ Name | Decription
 `base_sha` | The head sha of the branch the pull request will merge into.
 `head_ref` | The name of the pull request branch the comment belongs to.
 `head_sha` | The head sha of the pull request branch the comment belongs to.
+`merge_ref` | The refspec to the merged pull request.
 
 ## License
 
diff --git a/src/PullRequests.ts b/src/PullRequests.ts
index 59c4b1d..be7f547 100644
--- a/src/PullRequests.ts
+++ b/src/PullRequests.ts
@@ -72,5 +72,6 @@ export async function pullRequestDetails(token: string) {
     base_sha: baseRef.target.oid,
     head_ref: headRef.name,
     head_sha: headRef.target.oid,
+    merge_ref: 'refs/pull/' + context.issue.number + '/merge',
   };
 }
diff --git a/src/main.ts b/src/main.ts
index 14720a7..130399a 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -15,12 +15,14 @@ export async function run() {
       base_sha,
       head_ref,
       head_sha,
+      merge_ref,
     } = await pullRequestDetails(token);
 
     setOutput("base_ref", base_ref);
     setOutput("base_sha", base_sha);
     setOutput("head_ref", head_ref);
     setOutput("head_sha", head_sha);
+    setOutput("merge_ref", merge_ref);
   } catch (error) {
     if (error instanceof Error) {
       setFailed(error.message);