diff --git a/server/internal/ops/app/ip_region.go b/server/internal/ops/app/ip_region.go
index 189a1dc..4bdb3dd 100644
--- a/server/internal/ops/app/ip_region.go
+++ b/server/internal/ops/app/ip_region.go
@@ -7,6 +7,7 @@ import (
 	"net"
 	"os"
 	"strings"
+	"sync"
 
 	"go.uber.org/zap"
 
@@ -152,8 +153,10 @@ func (r *IPRegionResolver) Lookup(rawIP string) string {
 }
 
 type bufferIPRegionSearcher struct {
-	v4 *xdb.Searcher
-	v6 *xdb.Searcher
+	v4   *xdb.Searcher
+	v4Mu sync.Mutex
+	v6   *xdb.Searcher
+	v6Mu sync.Mutex
 }
 
 func (s *bufferIPRegionSearcher) Search(ip any) (string, error) {
@@ -166,11 +169,15 @@ func (s *bufferIPRegionSearcher) Search(ip any) (string, error) {
 		if s == nil || s.v4 == nil {
 			return "", nil
 		}
+		s.v4Mu.Lock()
+		defer s.v4Mu.Unlock()
 		return s.v4.Search(ipBytes)
 	case xdb.IPv6.Bytes:
 		if s == nil || s.v6 == nil {
 			return "", nil
 		}
+		s.v6Mu.Lock()
+		defer s.v6Mu.Unlock()
 		return s.v6.Search(ipBytes)
 	default:
 		return "", fmt.Errorf("invalid byte ip address with len=%d", len(ipBytes))