diff --git a/.gitea/workflows/diagnose.yaml b/.gitea/workflows/diagnose.yaml
index 994f1cb..32f3d42 100644
--- a/.gitea/workflows/diagnose.yaml
+++ b/.gitea/workflows/diagnose.yaml
@@ -1,5 +1,5 @@
 
-name: Diagnose GitHub mirror
+name: Diagnose GitHub sync
 
 on:
   push:
@@ -11,16 +11,24 @@ jobs:
   diagnose:
     runs-on: ubuntu-latest
     steps:
-      - name: Check source and credentials
+      - name: Check GitHub access
         env:
           GH_TOKEN: ${{ secrets.GH_TOKEN }}
         run: |
           set -eu
-          echo "Triggered ref: $GITHUB_REF"
-          echo "Source commit: $GITHUB_SHA"
-          if [ -z "$GH_TOKEN" ]; then
-            echo "ERROR: GH_TOKEN is empty or unavailable"
-            exit 1
-          fi
-          echo "GitHub token is present"
-          git --version
+
+          REPO="tafakkur/PyNix-Website"
+          AUTH="$(printf 'x-access-token:%s' "$GH_TOKEN" | base64 | tr -d '\n')"
+
+          git_auth() {
+            git -c http.extraheader="AUTHORIZATION: basic $AUTH" "$@"
+          }
+
+          echo "Checking GitHub repository access..."
+          git_auth ls-remote \
+            "https://github.com/${REPO}.git" refs/heads/main
+
+          echo "Checking source commit..."
+          echo "$GITHUB_SHA"
+
+          echo "GitHub read access succeeded."