diff --git a/agent/xds/clusters.go b/agent/xds/clusters.go
index db99104375..ff36277da5 100644
--- a/agent/xds/clusters.go
+++ b/agent/xds/clusters.go
@@ -59,6 +59,7 @@ func (s *Server) clustersFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapsh
 	// In transparent proxy mode there needs to be a passthrough cluster for traffic going to destinations
 	// that aren't in Consul's catalog.
 	if cfgSnap.Proxy.Mode == structs.ProxyModeTransparent &&
+		cfgSnap.ConnectProxy.ClusterConfig != nil &&
 		!cfgSnap.ConnectProxy.ClusterConfig.TransparentProxy.CatalogDestinationsOnly {
 
 		clusters = append(clusters, &envoy_cluster_v3.Cluster{