diff --git a/weaver/weave b/weaver/weave
index a06b3d08..5766717c 100755
--- a/weaver/weave
+++ b/weaver/weave
@@ -39,15 +39,15 @@ shift 2
     ip link set dev $BRIDGE up
 }
 
-# We set the router name to the bridge mac since that is stable across
-# re-creations of the containers.
-#
-# TODO use the mac of one of the physical host interfaces (eth0,
-# wlan0, etc) so the name becomes stable across host restarts.
-MACADDR=`cat /sys/class/net/$BRIDGE/address`
-
 case "$COMMAND" in
     launch)
+        # We set the router name to the bridge mac since that is
+        # stable across re-creations of the containers.
+        #
+        # TODO use the mac of one of the physical host interfaces
+        # (eth0, wlan0, etc) so the name becomes stable across host
+        # restarts.
+        MACADDR=`cat /sys/class/net/$BRIDGE/address`
         CONTAINER=$(docker run --privileged -d --name=weave -p 6783:6783/tcp -p 6783:6783/udp $WEAVE_DOCKER_ARGS zettio/weave -name $MACADDR "$@")
         IFACE=eth0
         ;;