diff --git a/src/release_engine.py b/src/release_engine.py
index f471174..e86a74b 100644
--- a/src/release_engine.py
+++ b/src/release_engine.py
@@ -147,6 +147,8 @@ class GiteaClient:
                 return json.loads(raw) if raw else None
         except error.HTTPError as exc:
             detail = exc.read().decode(errors="replace")
+            if exc.code == 401:
+                detail += " (authentication rejected; refresh the cron GITEA_TOKEN)"
             raise RuntimeError(f"Gitea {method} {path} failed: HTTP {exc.code}: {detail}") from exc
 
     @staticmethod
diff --git a/tests/test_release_engine.py b/tests/test_release_engine.py
index 9062a49..3286f40 100644
--- a/tests/test_release_engine.py
+++ b/tests/test_release_engine.py
@@ -1,4 +1,6 @@
 import json
+import threading
+from http.server import BaseHTTPRequestHandler, HTTPServer
 from pathlib import Path
 
 import pytest
@@ -6,6 +8,7 @@ import pytest
 from src.release_engine import (
     CommandResult,
     EngineConfig,
+    GiteaClient,
     Issue,
     ReleaseEngine,
     RunState,
@@ -15,6 +18,28 @@ from src.release_engine import (
 )
 
 
+def test_stale_token_error_explains_how_to_restore_cron_authentication():
+    class UnauthorizedHandler(BaseHTTPRequestHandler):
+        def do_GET(self):
+            self.send_response(401)
+            self.end_headers()
+            self.wfile.write(b'{"message":"user does not exist [uid: 0, name: ]"}')
+
+        def log_message(self, format, *args):
+            pass
+
+    server = HTTPServer(("127.0.0.1", 0), UnauthorizedHandler)
+    thread = threading.Thread(target=server.handle_request)
+    thread.start()
+    try:
+        client = GiteaClient(f"http://127.0.0.1:{server.server_port}", "stale-token")
+        with pytest.raises(RuntimeError, match="refresh the cron GITEA_TOKEN"):
+            client.list_open_issues("stackchain/stackchain-dashboard")
+    finally:
+        thread.join(timeout=2)
+        server.server_close()
+
+
 class FakeClient:
     def __init__(self, issues, verified_assignee="timmy", existing_pr=None):
         self.issues = issues