diff --git a/run/network.sh b/run/network.sh
index a042365..e72da3f 100644
--- a/run/network.sh
+++ b/run/network.sh
@@ -8,7 +8,7 @@ set -Eeuo pipefail
 
 : ${VM_NET_TAP:='dsm'}
 : ${VM_NET_DEV:='eth0'}
-: ${VM_NET_MAC:="${MAC}"}
+: ${VM_NET_MAC:="$MAC"}
 : ${VM_NET_HOST:='VirtualDSM'}
 
 : ${DNS_SERVERS:=''}