diff --git a/miner/worker.go b/miner/worker.go
index dcce308ab..a9f00ed99 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -925,7 +925,10 @@ func (w *worker) commitNewWork(interrupt *int32, noempty bool, timestamp int64)
 		header.Coinbase = w.coinbase
 	}
 	if err := w.engine.Prepare(w.chain, header); err != nil {
-		log.Error("Failed to prepare header for mining", "err", err)
+		// Ignore ErrUnauthorizedValidator, miner.etherbase is not unlocked
+		if _, ok := err.(*consensus.ErrUnauthorizedValidator); !ok {
+			log.Error("Failed to prepare header for mining", "err", err)
+		}
 		return
 	}
 	// If we are care about TheDAO hard-fork check whether to override the extra-data or not