diff --git a/README.md b/README.md
index 5a8e90d..57d8407 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,7 @@ or compact `system` / `user` fields. The completed job result contains
 - `WORKER_ID`, default hostname
 - `WORKER_POLL_INTERVAL`, default `2s`
 - `WORKER_CLAIM_LIMIT`, default `4`
+- `WORKER_LEASE_TIMEOUT`, default `15m`
 
 ## Next integration step
 
diff --git a/cmd/worker/main.go b/cmd/worker/main.go
index a1365a6..2aa8dd1 100644
--- a/cmd/worker/main.go
+++ b/cmd/worker/main.go
@@ -41,12 +41,13 @@ func main() {
 	}
 
 	llmClient := llm.New(cfg.LLMBaseURL, cfg.LLMAPIKey, cfg.LLMModel, cfg.LLMTimeout)
-	w := worker.New(db, llmClient, cfg.WorkerID, cfg.LLMModel, cfg.WorkerPollInterval, cfg.WorkerClaimLimit)
+	w := worker.New(db, llmClient, cfg.WorkerID, cfg.LLMModel, cfg.WorkerPollInterval, cfg.WorkerLeaseTimeout, cfg.WorkerClaimLimit)
 
 	slog.Info("ai_worker_started",
 		"worker_id", cfg.WorkerID,
 		"model", cfg.LLMModel,
 		"poll_interval", cfg.WorkerPollInterval.String(),
+		"lease_timeout", cfg.WorkerLeaseTimeout.String(),
 		"claim_limit", cfg.WorkerClaimLimit,
 	)
 	w.Run(ctx)
diff --git a/internal/config/config.go b/internal/config/config.go
index 5df8abb..284e7b8 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -21,6 +21,7 @@ type Config struct {
 	WorkerID           string
 	WorkerPollInterval time.Duration
 	WorkerClaimLimit   int
+	WorkerLeaseTimeout time.Duration
 }
 
 func Load() Config {
@@ -39,6 +40,7 @@ func Load() Config {
 		WorkerID:           envString("WORKER_ID", hostname()),
 		WorkerPollInterval: envDuration("WORKER_POLL_INTERVAL", 2*time.Second),
 		WorkerClaimLimit:   envInt("WORKER_CLAIM_LIMIT", 4),
+		WorkerLeaseTimeout: envDuration("WORKER_LEASE_TIMEOUT", 15*time.Minute),
 	}
 }
 
diff --git a/internal/store/store.go b/internal/store/store.go
index 07dbb79..1fe7359 100644
--- a/internal/store/store.go
+++ b/internal/store/store.go
@@ -264,6 +264,44 @@ RETURNING ` + jobSelectColumns + `
 	return job, err
 }
 
+func (s *Store) RequeueStaleRunning(ctx context.Context, olderThan time.Duration, limit int) (int, error) {
+	if olderThan <= 0 {
+		olderThan = 15 * time.Minute
+	}
+	if limit <= 0 {
+		limit = 100
+	}
+	if limit > 1000 {
+		limit = 1000
+	}
+	const q = `
+WITH picked AS (
+  SELECT id
+  FROM ai_jobs
+  WHERE status = 'running'
+    AND COALESCE(heartbeat_at, started_at, updated_at) < NOW() - make_interval(secs => $1)
+  ORDER BY COALESCE(heartbeat_at, started_at, updated_at) ASC
+  LIMIT $2
+)
+UPDATE ai_jobs j
+SET status = CASE WHEN j.attempts < j.max_attempts THEN 'pending' ELSE 'failed' END,
+    error_code = CASE WHEN j.attempts < j.max_attempts THEN NULL ELSE 'stale_worker' END,
+    error_message = CASE WHEN j.attempts < j.max_attempts THEN NULL ELSE 'worker lease expired' END,
+    worker_id = NULL,
+    heartbeat_at = NULL,
+    completed_at = CASE WHEN j.attempts < j.max_attempts THEN NULL ELSE NOW() END,
+    scheduled_at = CASE WHEN j.attempts < j.max_attempts THEN NOW() ELSE j.scheduled_at END,
+    updated_at = NOW()
+FROM picked
+WHERE j.id = picked.id
+`
+	tag, err := s.pool.Exec(ctx, q, int(olderThan.Seconds()), limit)
+	if err != nil {
+		return 0, err
+	}
+	return int(tag.RowsAffected()), nil
+}
+
 func (s *Store) Stats(ctx context.Context) (*model.Stats, error) {
 	out := &model.Stats{At: time.Now().UTC()}
 
diff --git a/internal/worker/worker.go b/internal/worker/worker.go
index ff46055..c58d353 100644
--- a/internal/worker/worker.go
+++ b/internal/worker/worker.go
@@ -24,12 +24,16 @@ type Worker struct {
 	modelProfile string
 	pollInterval time.Duration
 	claimLimit   int
+	leaseTimeout time.Duration
 }
 
-func New(store *store.Store, llmClient *llm.Client, workerID, modelProfile string, pollInterval time.Duration, claimLimit int) *Worker {
+func New(store *store.Store, llmClient *llm.Client, workerID, modelProfile string, pollInterval, leaseTimeout time.Duration, claimLimit int) *Worker {
 	if pollInterval <= 0 {
 		pollInterval = 2 * time.Second
 	}
+	if leaseTimeout <= 0 {
+		leaseTimeout = 15 * time.Minute
+	}
 	if claimLimit <= 0 {
 		claimLimit = 4
 	}
@@ -43,6 +47,7 @@ func New(store *store.Store, llmClient *llm.Client, workerID, modelProfile strin
 		modelProfile: modelProfile,
 		pollInterval: pollInterval,
 		claimLimit:   claimLimit,
+		leaseTimeout: leaseTimeout,
 	}
 }
 
@@ -60,6 +65,11 @@ func (w *Worker) Run(ctx context.Context) {
 }
 
 func (w *Worker) tick(ctx context.Context) {
+	if reset, err := w.store.RequeueStaleRunning(ctx, w.leaseTimeout, 100); err != nil {
+		slog.Error("requeue stale jobs failed", "error", err)
+	} else if reset > 0 {
+		slog.Warn("requeued stale jobs", "count", reset)
+	}
 	jobs, err := w.store.ClaimJobs(ctx, model.ClaimJobs{
 		WorkerID:      w.workerID,
 		TaskTypes:     []string{TaskLLMChat, TaskChatCompletion},
diff --git a/k8s/configmap.yaml b/k8s/configmap.yaml
index 53d21f4..bcada4c 100644
--- a/k8s/configmap.yaml
+++ b/k8s/configmap.yaml
@@ -14,3 +14,4 @@ data:
   WHISPERX_URL: "http://10.2.3.5:8001"
   WORKER_POLL_INTERVAL: "2s"
   WORKER_CLAIM_LIMIT: "4"
+  WORKER_LEASE_TIMEOUT: "15m"