diff --git a/packages/app/server/routes/check.post.ts b/packages/app/server/routes/check.post.ts
index dbbe8146..8a900b05 100644
--- a/packages/app/server/routes/check.post.ts
+++ b/packages/app/server/routes/check.post.ts
@@ -17,18 +17,28 @@ export default eventHandler(async (event) => {
       authenticated = true;
     } catch {}
 
-    try {
-      await app.octokit.request("GET /orgs/{org}/installation", {
-        org: owner,
-      });
-      authenticated = true;
-    } catch {}
+    if (!authenticated) {
+      try {
+        const { data: installation } = await app.octokit.request(
+          "GET /orgs/{org}/installation",
+          { org: owner },
+        );
+        const installationOctokit = await app.getInstallationOctokit(
+          installation.id,
+        );
+        await installationOctokit.request("GET /repos/{owner}/{repo}", {
+          owner,
+          repo,
+        });
+        authenticated = true;
+      } catch {}
+    }
 
     if (!authenticated) {
       throw createError({
         statusCode: 404,
         fatal: true,
-        message: `The app https://github.com/apps/pkg-pr-new is not installed on ${owner}/${repo}.`,
+        message: `The app https://github.com/apps/pkg-pr-new is not installed on or does not have access to ${owner}/${repo}.`,
       });
     }