diff --git a/gvisor.go b/gvisor.go
index 972302a..81e8efd 100644
--- a/gvisor.go
+++ b/gvisor.go
@@ -175,7 +175,7 @@ func (t *GVisor) Start() error {
 				}
 			})
 			switch actionType := action.(type) {
-			case *ActionReject:
+			case *ActionBlock:
 				// TODO: send icmp unreachable
 				return true
 			case *ActionDirect:
@@ -238,7 +238,7 @@ func (t *GVisor) Start() error {
 					}
 				})
 				switch actionType := action.(type) {
-				case *ActionReject:
+				case *ActionBlock:
 					// TODO: send icmp unreachable
 					return true
 				case *ActionDirect:
diff --git a/route.go b/route.go
index 91c91a5..0ebf267 100644
--- a/route.go
+++ b/route.go
@@ -9,8 +9,9 @@ import (
 type ActionType = uint8
 
 const (
-	ActionTypeReturn ActionType = iota
-	ActionTypeReject
+	ActionTypeUnknown ActionType = iota
+	ActionTypeReturn
+	ActionTypeBlock
 	ActionTypeDirect
 )
 
@@ -18,8 +19,8 @@ func ParseActionType(action string) (ActionType, error) {
 	switch action {
 	case "return":
 		return ActionTypeReturn, nil
-	case "reject":
-		return ActionTypeReject, nil
+	case "block":
+		return ActionTypeBlock, nil
 	case "direct":
 		return ActionTypeDirect, nil
 	default:
@@ -27,16 +28,18 @@ func ParseActionType(action string) (ActionType, error) {
 	}
 }
 
-func ActionTypeName(actionType ActionType) string {
+func ActionTypeName(actionType ActionType) (string, error) {
 	switch actionType {
+	case ActionTypeUnknown:
+		return "", nil
 	case ActionTypeReturn:
-		return "return"
-	case ActionTypeReject:
-		return "reject"
+		return "return", nil
+	case ActionTypeBlock:
+		return "block", nil
 	case ActionTypeDirect:
-		return "direct"
+		return "direct", nil
 	default:
-		return "unknown"
+		return "", E.New("unknown action: ", actionType)
 	}
 }
 
@@ -70,13 +73,13 @@ func (r *ActionReturn) Timeout() bool {
 	return false
 }
 
-type ActionReject struct{}
+type ActionBlock struct{}
 
-func (r *ActionReject) ActionType() ActionType {
-	return ActionTypeReject
+func (r *ActionBlock) ActionType() ActionType {
+	return ActionTypeBlock
 }
 
-func (r *ActionReject) Timeout() bool {
+func (r *ActionBlock) Timeout() bool {
 	return false
 }
 
diff --git a/system.go b/system.go
index e3e77eb..a5359d5 100644
--- a/system.go
+++ b/system.go
@@ -257,7 +257,7 @@ func (s *System) processIPv4TCP(packet clashtcpip.IPv4Packet, header clashtcpip.
 				return s.router.RouteConnection(session, &systemTCPDirectPacketWriter4{s.tun, source})
 			})
 			switch actionType := action.(type) {
-			case *ActionReject:
+			case *ActionBlock:
 				// TODO: send ICMP unreachable
 				return nil
 			case *ActionDirect:
@@ -298,7 +298,7 @@ func (s *System) processIPv6TCP(packet clashtcpip.IPv6Packet, header clashtcpip.
 				return s.router.RouteConnection(session, &systemTCPDirectPacketWriter6{s.tun, source})
 			})
 			switch actionType := action.(type) {
-			case *ActionReject:
+			case *ActionBlock:
 				// TODO: send RST
 				return nil
 			case *ActionDirect:
@@ -336,7 +336,7 @@ func (s *System) processIPv4UDP(packet clashtcpip.IPv4Packet, header clashtcpip.
 			return s.router.RouteConnection(routeSession, &systemUDPDirectPacketWriter4{s.tun, source})
 		})
 		switch actionType := action.(type) {
-		case *ActionReject:
+		case *ActionBlock:
 			// TODO: send icmp unreachable
 			return nil
 		case *ActionDirect:
@@ -374,7 +374,7 @@ func (s *System) processIPv6UDP(packet clashtcpip.IPv6Packet, header clashtcpip.
 			return s.router.RouteConnection(routeSession, &systemUDPDirectPacketWriter6{s.tun, source})
 		})
 		switch actionType := action.(type) {
-		case *ActionReject:
+		case *ActionBlock:
 			// TODO: send icmp unreachable
 			return nil
 		case *ActionDirect:
@@ -407,7 +407,7 @@ func (s *System) processIPv4ICMP(packet clashtcpip.IPv4Packet, header clashtcpip
 			return s.router.RouteConnection(routeSession, &systemICMPDirectPacketWriter4{s.tun, packet.SourceIP()})
 		})
 		switch actionType := action.(type) {
-		case *ActionReject:
+		case *ActionBlock:
 			// TODO: send icmp unreachable
 			return nil
 		case *ActionDirect:
@@ -435,7 +435,7 @@ func (s *System) processIPv6ICMP(packet clashtcpip.IPv6Packet, header clashtcpip
 			return s.router.RouteConnection(routeSession, &systemICMPDirectPacketWriter6{s.tun, packet.SourceIP()})
 		})
 		switch actionType := action.(type) {
-		case *ActionReject:
+		case *ActionBlock:
 			// TODO: send icmp unreachable
 			return nil
 		case *ActionDirect: