diff --git a/cmd/tools/segment-verify/process.go b/cmd/tools/segment-verify/process.go
index 149f9f1c9..f9fde00c5 100644
--- a/cmd/tools/segment-verify/process.go
+++ b/cmd/tools/segment-verify/process.go
@@ -140,8 +140,12 @@ func (service *Service) VerifyBatches(ctx context.Context, batches []*Batch) err
 
 // convertAliasToNodeURL converts a node alias to node url, using a cache if needed.
 func (service *Service) convertAliasToNodeURL(ctx context.Context, alias metabase.NodeAlias) (_ storj.NodeURL, err error) {
+	service.mu.RLock()
 	nodeURL, ok := service.aliasToNodeURL[alias]
+	service.mu.RUnlock()
 	if !ok {
+		service.mu.Lock()
+		defer service.mu.Unlock()
 		nodeID, ok := service.aliasMap.Node(alias)
 		if !ok {
 			latest, err := service.metabase.LatestNodesAliasMap(ctx)
diff --git a/cmd/tools/segment-verify/service.go b/cmd/tools/segment-verify/service.go
index e15628c95..04c070a20 100644
--- a/cmd/tools/segment-verify/service.go
+++ b/cmd/tools/segment-verify/service.go
@@ -10,6 +10,7 @@ import (
 	"io"
 	"os"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"
 
@@ -94,8 +95,9 @@ type Service struct {
 	verifier Verifier
 	overlay  Overlay
 
-	aliasMap        *metabase.NodeAliasMap
+	mu              sync.RWMutex
 	aliasToNodeURL  map[metabase.NodeAlias]storj.NodeURL
+	aliasMap        *metabase.NodeAliasMap
 	priorityNodes   NodeAliasSet
 	ignoreNodes     NodeAliasSet
 	offlineNodes    *nodeAliasExpiringSet