diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 8315ec2d48..7152cf450a 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -123,6 +123,10 @@ var (
 	// turn of the signer.
 	errWrongDifficulty = errors.New("wrong difficulty")
 
+	// errInvalidTimestamp is returned if the timestamp of a block is lower than
+	// the previous block's timestamp + the minimum block period.
+	errInvalidTimestamp = errors.New("invalid timestamp")
+
 	// errInvalidVotingChain is returned if an authorization list is attempted to
 	// be modified via out-of-range or non-contiguous headers.
 	errInvalidVotingChain = errors.New("invalid voting chain")
@@ -323,9 +327,9 @@ func (c *Clique) verifyCascadingFields(chain consensus.ChainHeaderReader, header
 	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
 		return consensus.ErrUnknownAncestor
 	}
-	/*if parent.Time+c.config.Period > header.Time {
+	if parent.Time+c.config.Period > header.Time {
 		return errInvalidTimestamp
-	}*/
+	}
 	// Verify that the gasUsed is <= gasLimit
 	if header.GasUsed > header.GasLimit {
 		return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit)
@@ -549,10 +553,10 @@ func (c *Clique) Prepare(chain consensus.ChainHeaderReader, header *types.Header
 	if parent == nil {
 		return consensus.ErrUnknownAncestor
 	}
-	//header.Time = parent.Time + c.config.Period
-	//if header.Time < uint64(time.Now().Unix()) {
-	header.Time = uint64(time.Now().Unix())
-	//}
+	header.Time = parent.Time + c.config.Period
+	if header.Time < uint64(time.Now().Unix()) {
+		header.Time = uint64(time.Now().Unix())
+	}
 	return nil
 }
 
diff --git a/miner/worker.go b/miner/worker.go
index e0e56f8f3f..855a8ba898 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -400,7 +400,7 @@ func (w *worker) newWorkLoop(recommit time.Duration) {
 		case head := <-w.chainHeadCh:
 			clearPending(head.Block.NumberU64())
 			timestamp = time.Now().Unix()
-			// commit(false, commitInterruptNewHead)
+			commit(true, commitInterruptNewHead)
 
 		case <-timer.C:
 			// If mining is running resubmit a new work cycle periodically to pull in