diff --git a/miner/worker.go b/miner/worker.go
index 4a9528c395..25fe0d3fd9 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -965,7 +965,9 @@ func (w *worker) commit(uncles []*types.Header, interval func(), update bool, st
 		*receipts[i] = *l
 	}
 	s := w.current.state.Copy()
-	block, err := w.engine.FinalizeAndAssemble(w.chain, w.current.header, s, w.current.txs, uncles, w.current.receipts)
+	h := new(types.Header)
+	*h = *w.current.header
+	block, err := w.engine.FinalizeAndAssemble(w.chain, h, s, w.current.txs, uncles, w.current.receipts)
 	if err != nil {
 		return err
 	}