diff --git a/plugins/main/macvlan/macvlan.go b/plugins/main/macvlan/macvlan.go
index 4fe11772..af24971c 100644
--- a/plugins/main/macvlan/macvlan.go
+++ b/plugins/main/macvlan/macvlan.go
@@ -148,7 +148,8 @@ func getMTUByName(ifName string, namespace string, inContainer bool) (int, error
 	var link netlink.Link
 	var err error
 	if inContainer {
-		netns, err := ns.GetNS(namespace)
+		var netns ns.NetNS
+		netns, err = ns.GetNS(namespace)
 		if err != nil {
 			return 0, fmt.Errorf("failed to open netns %q: %v", netns, err)
 		}
diff --git a/plugins/main/vlan/vlan.go b/plugins/main/vlan/vlan.go
index 8da3fe1b..a6bceeef 100644
--- a/plugins/main/vlan/vlan.go
+++ b/plugins/main/vlan/vlan.go
@@ -75,7 +75,8 @@ func getMTUByName(ifName string, namespace string, inContainer bool) (int, error
 	var link netlink.Link
 	var err error
 	if inContainer {
-		netns, err := ns.GetNS(namespace)
+		var netns ns.NetNS
+		netns, err = ns.GetNS(namespace)
 		if err != nil {
 			return 0, fmt.Errorf("failed to open netns %q: %v", netns, err)
 		}