diff --git a/pkg/agent/core/ngt/handler/grpc/remove.go b/pkg/agent/core/ngt/handler/grpc/remove.go
index 03442372009..4d3c7132c2b 100644
--- a/pkg/agent/core/ngt/handler/grpc/remove.go
+++ b/pkg/agent/core/ngt/handler/grpc/remove.go
@@ -16,7 +16,6 @@ package grpc
 import (
 	"context"
 	"fmt"
-	"sync"
 
 	"github.com/vdaas/vald/apis/grpc/v1/payload"
 	"github.com/vdaas/vald/apis/grpc/v1/vald"
@@ -29,6 +28,7 @@ import (
 	"github.com/vdaas/vald/internal/net/grpc/status"
 	"github.com/vdaas/vald/internal/observability/trace"
 	"github.com/vdaas/vald/internal/strings"
+	"github.com/vdaas/vald/internal/sync"
 	"go.opentelemetry.io/otel/attribute"
 )