diff --git a/integration/netconfig/netconfig_test.go b/integration/netconfig/netconfig_test.go
index 92284c9..540c8ad 100644
--- a/integration/netconfig/netconfig_test.go
+++ b/integration/netconfig/netconfig_test.go
@@ -46,7 +46,8 @@ const goldenInterfaces = `
       "hardware_addr": "02:73:53:00:b0:0c",
       "spoof_hardware_addr": "02:73:53:00:b0:aa",
       "name": "lan0",
-      "addr": "192.168.42.1/24"
+      "addr": "192.168.42.1/24",
+      "mtu": 1492
     },
     {
       "name": "wg0",
@@ -393,6 +394,9 @@ func TestNetconfig(t *testing.T) {
 		if !strings.Contains(string(link), "link/ether 02:73:53:00:b0:aa") {
 			t.Errorf("lan0 MAC address is not 02:73:53:00:b0:aa")
 		}
+		if !strings.Contains(string(link), " mtu 1492 ") {
+			t.Errorf("lan0 MTU is not 1492 (link: %q)", string(link))
+		}
 
 		addrs, err := exec.Command("ip", "-netns", ns, "address", "show", "dev", "uplink0").Output()
 		if err != nil {
diff --git a/internal/netconfig/netconfig.go b/internal/netconfig/netconfig.go
index 597355a..14e5c03 100644
--- a/internal/netconfig/netconfig.go
+++ b/internal/netconfig/netconfig.go
@@ -268,6 +268,7 @@ type InterfaceDetails struct {
 	Addr              string   `json:"addr"`                // e.g. 192.168.42.1/24
 	ExtraAddrs        []string `json:"extra_addrs"`         // e.g. ["192.168.23.1/24"]
 	ExtraRoutes       []Route  `json:"extra_routes"`
+	MTU               int      `json:"mtu"` // e.g. 1492 for PPPoE connections
 }
 
 type BridgeDetails struct {
@@ -422,6 +423,12 @@ func applyInterfaces(dir, root string, cfg InterfaceConfig) error {
 			attr.Name = details.Name
 		}
 
+		if details.MTU != 0 {
+			if err := netlink.LinkSetMTU(l, details.MTU); err != nil {
+				return fmt.Errorf("LinkSetMTU(%d): %v", details.MTU, err)
+			}
+		}
+
 		if spoof := details.SpoofHardwareAddr; spoof != "" {
 			hwaddr, err := net.ParseMAC(spoof)
 			if err != nil {