diff --git a/consensus/istanbul/config.go b/consensus/istanbul/config.go
index cb97ccaebceb..815154f348d1 100644
--- a/consensus/istanbul/config.go
+++ b/consensus/istanbul/config.go
@@ -28,7 +28,7 @@ type FaultyMode uint64
 const (
 	// Disabled disables the faulty mode
 	Disabled FaultyMode = iota
-	// Random selects one attack randomly
+	// Random attacks randomly
 	Random
 	// NotBroadcast doesn't broadcast any messages to other validators
 	NotBroadcast
@@ -38,6 +38,8 @@ const (
 	ModifySig
 	// AlwaysPropose always proposes a proposal to validators
 	AlwaysPropose
+	// AlwaysRoundChange always sends round change while receiving messages
+	AlwaysRoundChange
 )
 
 func (f FaultyMode) Uint64() uint64 {
@@ -58,6 +60,8 @@ func (f FaultyMode) String() string {
 		return "ModifySig"
 	case AlwaysPropose:
 		return "AlwaysPropose"
+	case AlwaysRoundChange:
+		return "AlwaysRoundChange"
 	default:
 		return "Undefined"
 	}
diff --git a/consensus/istanbul/core/faulty/faulty.go b/consensus/istanbul/core/faulty/faulty.go
index 89763ef42c42..be2b1b646858 100644
--- a/consensus/istanbul/core/faulty/faulty.go
+++ b/consensus/istanbul/core/faulty/faulty.go
@@ -41,3 +41,7 @@ func (c *core) modifySig() bool {
 func (c *core) alwaysPropose() bool {
 	return c.config.FaultyMode == istanbul.AlwaysPropose.Uint64() || c.random()
 }
+
+func (c *core) alwaysRoundChange() bool {
+	return c.config.FaultyMode == istanbul.AlwaysRoundChange.Uint64() || c.random()
+}
diff --git a/consensus/istanbul/core/faulty/handler.go b/consensus/istanbul/core/faulty/handler.go
index dbfbc9aad9fd..8e61acc8e3eb 100644
--- a/consensus/istanbul/core/faulty/handler.go
+++ b/consensus/istanbul/core/faulty/handler.go
@@ -164,6 +164,11 @@ func (c *core) handleCheckedMsg(msg *message, src istanbul.Validator) error {
 		return err
 	}
 
+	if msg.Code != msgRoundChange && c.alwaysRoundChange() {
+		logger.Info("Send faulty round change", "round", c.current.Round().Uint64())
+		c.sendNextRoundChange()
+		return nil
+	}
 	switch msg.Code {
 	case msgPreprepare:
 		return testBacklog(c.handlePreprepare(msg, src))