diff --git a/server/grpc_service.go b/server/grpc_service.go
index b1fd840e6f7..7c587ac18b8 100644
--- a/server/grpc_service.go
+++ b/server/grpc_service.go
@@ -203,6 +203,10 @@ func (s *GrpcServer) Tso(stream pdpb.PD_TsoServer) error {
 			return errors.WithStack(err)
 		}
 
+		// TSO uses leader lease to determine validity. No need to check leader here.
+		if s.IsClosed() {
+			return ErrNotStarted
+		}
 		if forwardedHost, err := s.getForwardedHost(ctx, stream.Context()); err != nil {
 			return err
 		} else if len(forwardedHost) > 0 {
@@ -230,10 +234,6 @@ func (s *GrpcServer) Tso(stream pdpb.PD_TsoServer) error {
 		}
 
 		start := time.Now()
-		// TSO uses leader lease to determine validity. No need to check leader here.
-		if s.IsClosed() {
-			return status.Errorf(codes.Unknown, "server not started")
-		}
 		if request.GetHeader().GetClusterId() != s.clusterID {
 			return status.Errorf(codes.FailedPrecondition, "mismatch cluster id, need %d but got %d", s.clusterID, request.GetHeader().GetClusterId())
 		}
@@ -345,6 +345,9 @@ func (s *GrpcServer) AllocID(ctx context.Context, request *pdpb.AllocIDRequest)
 
 // IsSnapshotRecovering implements gRPC PDServer.
 func (s *GrpcServer) IsSnapshotRecovering(ctx context.Context, request *pdpb.IsSnapshotRecoveringRequest) (*pdpb.IsSnapshotRecoveringResponse, error) {
+	if s.IsClosed() {
+		return nil, ErrNotStarted
+	}
 	// recovering mark is stored in etcd directly, there's no need to forward.
 	marked, err := s.Server.IsSnapshotRecovering(ctx)
 	if err != nil {