diff --git a/consensus/ibft/ibft.go b/consensus/ibft/ibft.go
index 82f910c736..81b66e49fb 100644
--- a/consensus/ibft/ibft.go
+++ b/consensus/ibft/ibft.go
@@ -900,11 +900,24 @@ func (i *Ibft) runValidateState() {
 		}
 
 		if msg == nil {
+			i.logger.Debug("ValidateState got message timeout, should change round",
+				"sequence", i.state.view.Sequence, "round", i.state.view.Round+1)
+			i.state.unlock()
 			i.setState(RoundChangeState)
 
 			continue
 		}
 
+		// check msg number and round, might from some faulty nodes
+		if i.state.view.Sequence != msg.View.GetSequence() ||
+			i.state.view.Round != msg.View.GetRound() {
+			i.logger.Debug("ValidateState got message not matching sequence and round",
+				"my-sequence", i.state.view.Sequence, "my-round", i.state.view.Round+1,
+				"other-sequence", msg.View.GetSequence(), "other-round", msg.View.GetRound())
+
+			continue
+		}
+
 		switch msg.Type {
 		case proto.MessageReq_Prepare:
 			i.state.addPrepared(msg)
diff --git a/contracts/abis/abis.go b/contracts/abis/abis.go
index 5506ef752d..9c939b951a 100644
--- a/contracts/abis/abis.go
+++ b/contracts/abis/abis.go
@@ -15,4 +15,7 @@ var (
 )
 
 // Temporarily deployed contract ABI
-var StressTestABI = abi.MustNewABI(StressTestJSONABI)
+var (
+	// StressTest contract abi
+	StressTestABI = abi.MustNewABI(StressTestJSONABI)
+)
diff --git a/e2e/framework/config.go b/e2e/framework/config.go
index 3458078160..87bc7fee5a 100644
--- a/e2e/framework/config.go
+++ b/e2e/framework/config.go
@@ -26,26 +26,27 @@ type SrvAccount struct {
 // TestServerConfig for the test server
 type TestServerConfig struct {
 	ReservedPorts           []ReservedPort
-	JSONRPCPort             int                  // The JSON RPC endpoint port
-	GRPCPort                int                  // The GRPC endpoint port
-	LibP2PPort              int                  // The Libp2p endpoint port
-	Seal                    bool                 // Flag indicating if blocks should be sealed
-	RootDir                 string               // The root directory for test environment
-	IBFTDirPrefix           string               // The prefix of data directory for IBFT
-	IBFTDir                 string               // The name of data directory for IBFT
-	PremineAccts            []*SrvAccount        // Accounts with existing balances (genesis accounts)
-	GenesisValidatorBalance *big.Int             // Genesis the balance for the validators
-	DevStakers              []types.Address      // List of initial staking addresses for the ValidatorSet SC with dev consensus
-	Consensus               ConsensusType        // Consensus MechanismType
-	Bootnodes               []string             // Bootnode Addresses
-	PriceLimit              *uint64              // Minimum gas price limit to enforce for acceptance into the pool
-	DevInterval             int                  // Dev consensus update interval [s]
-	EpochSize               uint64               // The epoch size in blocks for the IBFT layer
-	BlockGasLimit           uint64               // Block gas limit
-	BlockGasTarget          uint64               // Gas target for new blocks
-	ShowsLog                bool                 // Flag specifying if logs are shown
-	IsPos                   bool                 // Specifies the mechanism used for IBFT (PoA / PoS)
-	Signer                  *crypto.EIP155Signer // Signer used for transactions
+	JSONRPCPort             int           // The JSON RPC endpoint port
+	GRPCPort                int           // The GRPC endpoint port
+	LibP2PPort              int           // The Libp2p endpoint port
+	Seal                    bool          // Flag indicating if blocks should be sealed
+	RootDir                 string        // The root directory for test environment
+	IBFTDirPrefix           string        // The prefix of data directory for IBFT
+	IBFTDir                 string        // The name of data directory for IBFT
+	PremineAccts            []*SrvAccount // Accounts with existing balances (genesis accounts)
+	GenesisValidatorBalance *big.Int      // Genesis the balance for the validators
+	// List of initial staking addresses for the ValidatorSet SC with dev consensus
+	DevStakers     []types.Address
+	Consensus      ConsensusType        // Consensus MechanismType
+	Bootnodes      []string             // Bootnode Addresses
+	PriceLimit     *uint64              // Minimum gas price limit to enforce for acceptance into the pool
+	DevInterval    int                  // Dev consensus update interval [s]
+	EpochSize      uint64               // The epoch size in blocks for the IBFT layer
+	BlockGasLimit  uint64               // Block gas limit
+	BlockGasTarget uint64               // Gas target for new blocks
+	ShowsLog       bool                 // Flag specifying if logs are shown
+	IsPos          bool                 // Specifies the mechanism used for IBFT (PoA / PoS)
+	Signer         *crypto.EIP155Signer // Signer used for transactions
 }
 
 // DataDir returns path of data directory server uses