diff --git a/dhcp4/options.go b/dhcp4/options.go
index 34a2a3f..5ab6357 100644
--- a/dhcp4/options.go
+++ b/dhcp4/options.go
@@ -38,6 +38,7 @@ const (
 	OptHostname           Option = 12 // string
 	OptBootFileSize       Option = 13 // uint16
 	OptDomainName         Option = 15 // string
+	OptInterfaceMTU       Option = 26 // uint16
 	OptBroadcastAddr      Option = 28 // IP
 	OptNTPServers         Option = 42 // IP
 	OptVendorSpecific     Option = 43 // []byte