diff --git a/ethstorage/miner/l1_mining_api.go b/ethstorage/miner/l1_mining_api.go
index 32e8e70d..732c4ac9 100644
--- a/ethstorage/miner/l1_mining_api.go
+++ b/ethstorage/miner/l1_mining_api.go
@@ -170,7 +170,7 @@ func (m *l1MiningAPI) SubmitMinedResult(ctx context.Context, contract common.Add
 			"profitEstimated", weiToEther(profit),
 			"minimumProfit", weiToEther(cfg.MinimumProfit),
 		)
-		return common.Hash{}, fmt.Errorf("dropped: not enough profit")
+		return common.Hash{}, nil
 	}
 
 	chainID, err := m.NetworkID(ctx)
diff --git a/ethstorage/miner/worker.go b/ethstorage/miner/worker.go
index 62012c5e..46af37b2 100644
--- a/ethstorage/miner/worker.go
+++ b/ethstorage/miner/worker.go
@@ -31,6 +31,7 @@ const (
 
 var (
 	minedEventSig = crypto.Keccak256Hash([]byte("MinedBlock(uint256,uint256,uint256,uint256,address,uint256)"))
+	errCh         = make(chan miningError, 10)
 )
 
 type task struct {
@@ -54,6 +55,16 @@ func (t *taskItem) String() string {
 	return fmt.Sprintf("shard: %d, thread: %d, block: %v", t.shardIdx, t.thread, t.blockNumber)
 }
 
+type miningError struct {
+	shardIdx uint64
+	block    *big.Int
+	err      error
+}
+
+func (e miningError) String() string {
+	return fmt.Sprintf("shard %d: block %v: %s", e.shardIdx, e.block, e.err.Error())
+}
+
 type result struct {
 	blockNumber     *big.Int
 	startShardId    uint64
@@ -262,6 +273,11 @@ func (w *worker) taskLoop(taskCh chan *taskItem) {
 		case ti := <-taskCh:
 			success, err := w.mineTask(ti)
 			if err != nil {
+				select {
+				case errCh <- miningError{ti.shardIdx, ti.blockNumber, err}:
+				default:
+					w.lg.Warn("Sent miningError to errCh failed", "lenOfCh", len(errCh))
+				}
 				w.lg.Warn("Mine task fail", "shard", ti.shardIdx, "thread", ti.thread, "block", ti.blockNumber, "err", err.Error())
 			}
 			if success {
@@ -298,11 +314,6 @@ func (w *worker) notifyResultLoop() {
 // resultLoop is a standalone goroutine to submit mining result to L1 contract.
 func (w *worker) resultLoop() {
 	defer w.wg.Done()
-	type miningError struct {
-		shardIdx uint64
-		block    *big.Int
-		err      error
-	}
 	errorCache := make([]miningError, 0)
 	totalSubmitted := 0
 	ticker := time.NewTicker(1 * time.Minute)
@@ -353,6 +364,8 @@ func (w *worker) resultLoop() {
 			} else {
 				log.Info("Mining stats", "totalSubmitted", totalSubmitted, "totalErrors", len(errorCache))
 			}
+		case err := <-errCh:
+			errorCache = append(errorCache, err)
 		case <-w.exitCh:
 			w.lg.Warn("Worker is exiting from result loop...")
 			return