diff --git a/app/gitea.js b/app/gitea.js
index cbd59d4..6219f5a 100644
--- a/app/gitea.js
+++ b/app/gitea.js
@@ -41,14 +41,15 @@ export async function commitFile(filePath, content, message) {
     ...(sha ? { sha } : {}),
   };
 
-  console.log(`  [debug] ${sha ? 'PUT' : 'POST'} ${url} branch=${PR_HEAD_BRANCH}`);
+  console.log(`  [debug] ${sha ? 'PUT' : 'POST'} ${url} branch=${PR_HEAD_BRANCH} content_len=${encoded.length}`);
   const resp = await axios.request({
     method: sha ? 'put' : 'post',
     url,
-    headers: headers(),
+    headers: { ...headers(), 'Content-Type': 'application/json' },
     httpsAgent,
     timeout: 30000,
-    data: payload,
+    data: JSON.stringify(payload),
   });
+  console.log(`  [debug] response status=${resp.status}`);
   return resp.data;
 }