diff --git a/init/network.go b/init/network.go
index d4a98b72..ced409b3 100644
--- a/init/network.go
+++ b/init/network.go
@@ -6,6 +6,7 @@ import (
 	"net"
 	"os"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
@@ -69,7 +70,10 @@ func runDhcp(ifname string) error {
 }
 
 func shutdownNetwork() {
-	for _, ifname := range initializedIfnames {
+	initializedIfnames.Lock()
+	defer initializedIfnames.Unlock()
+
+	for _, ifname := range initializedIfnames.v {
 		debug("shutting down network interface %s", ifname)
 		link, err := netlink.LinkByName(ifname)
 		if err != nil {
@@ -90,7 +94,10 @@ func shutdownNetwork() {
 	}
 }
 
-var initializedIfnames []string
+var initializedIfnames = struct {
+	v []string
+	sync.Mutex
+}{}
 
 func initializeNetworkInterface(ifname string) error {
 	debug("%s: start initializing network interface", ifname)
@@ -109,7 +116,9 @@ func initializeNetworkInterface(ifname string) error {
 	if err := netlink.LinkSetUp(link); err != nil {
 		return err
 	}
-	initializedIfnames = append(initializedIfnames, ifname)
+	initializedIfnames.Lock()
+	initializedIfnames.v = append(initializedIfnames.v, ifname)
+	initializedIfnames.Unlock()
 
 	timeout := time.After(20 * time.Second)
 	debug("%s waiting interface to be UP", ifname)