diff --git a/eth/catalyst/api.go b/eth/catalyst/api.go
index 6f2d3e76b78e9..f149226749c20 100644
--- a/eth/catalyst/api.go
+++ b/eth/catalyst/api.go
@@ -305,8 +305,8 @@ func (api *ConsensusAPI) assembleBlock(parentHash common.Hash, params *PayloadAt
 		return nil, fmt.Errorf("cannot assemble block with unknown parent %s", parentHash)
 	}
 
-	if params.Timestamp < parent.Time() {
-		return nil, fmt.Errorf("child timestamp lower than parent's: %d < %d", params.Timestamp, parent.Time())
+	if params.Timestamp <= parent.Time() {
+		return nil, fmt.Errorf("child timestamp lower or equal to parent's: %d < %d", params.Timestamp, parent.Time())
 	}
 	if now := uint64(time.Now().Unix()); params.Timestamp > now+1 {
 		diff := time.Duration(params.Timestamp-now) * time.Second
diff --git a/eth/catalyst/api_test.go b/eth/catalyst/api_test.go
index aa5cb80eef1d3..53bdf3665f465 100644
--- a/eth/catalyst/api_test.go
+++ b/eth/catalyst/api_test.go
@@ -17,6 +17,7 @@
 package catalyst
 
 import (
+	"fmt"
 	"math/big"
 	"testing"
 	"time"
@@ -184,6 +185,48 @@ func checkLogEvents(t *testing.T, logsCh <-chan []*types.Log, rmLogsCh <-chan co
 	}
 }
 
+func TestInvalidPayloadTimestamp(t *testing.T) {
+	genesis, preMergeBlocks := generatePreMergeChain(10)
+	n, ethservice := startEthService(t, genesis, preMergeBlocks)
+	ethservice.Merger().ReachTTD()
+	defer n.Close()
+	var (
+		api    = NewConsensusAPI(ethservice, nil)
+		parent = ethservice.BlockChain().CurrentBlock()
+	)
+	tests := []struct {
+		time      uint64
+		shouldErr bool
+	}{
+		{0, true},
+		{parent.Time(), true},
+		{parent.Time() - 1, true},
+		{parent.Time() + 1, false},
+		{uint64(time.Now().Unix()) + uint64(time.Minute), false},
+	}
+
+	for i, test := range tests {
+		t.Run(fmt.Sprintf("Timestamp test: %v", i), func(t *testing.T) {
+			params := PayloadAttributesV1{
+				Timestamp:             test.time,
+				Random:                crypto.Keccak256Hash([]byte{byte(123)}),
+				SuggestedFeeRecipient: parent.Coinbase(),
+			}
+			fcState := ForkchoiceStateV1{
+				HeadBlockHash:      parent.Hash(),
+				SafeBlockHash:      common.Hash{},
+				FinalizedBlockHash: common.Hash{},
+			}
+			_, err := api.ForkchoiceUpdatedV1(fcState, &params)
+			if test.shouldErr && err == nil {
+				t.Fatalf("expected error preparing payload with invalid timestamp, err=%v", err)
+			} else if !test.shouldErr && err != nil {
+				t.Fatalf("error preparing payload with valid timestamp, err=%v", err)
+			}
+		})
+	}
+}
+
 func TestEth2NewBlock(t *testing.T) {
 	genesis, preMergeBlocks := generatePreMergeChain(10)
 	n, ethservice := startEthService(t, genesis, preMergeBlocks)
@@ -413,6 +456,5 @@ func TestFullAPI(t *testing.T) {
 			t.Fatalf("Chain head should be updated")
 		}
 		parent = ethservice.BlockChain().CurrentBlock()
-
 	}
 }