diff --git a/lib/nova b/lib/nova
index 6521cd7..df2b977 100644
--- a/lib/nova
+++ b/lib/nova
@@ -689,6 +689,8 @@
     iniset $NOVA_CONF DEFAULT public_interface "$PUBLIC_INTERFACE"
     iniset $NOVA_CONF DEFAULT vlan_interface "$VLAN_INTERFACE"
     iniset $NOVA_CONF DEFAULT flat_network_bridge "$FLAT_NETWORK_BRIDGE"
+    # force down dhcp leases to 5 minutes, which lets us expire faster
+    iniset $NOVA_CONF DEFAULT dhcp_lease_time 300
     if [ -n "$FLAT_INTERFACE" ]; then
         iniset $NOVA_CONF DEFAULT flat_interface "$FLAT_INTERFACE"
     fi