diff --git a/init.d/openwrt/functions b/init.d/openwrt/functions
index e3e5df8..09b7072 100644
--- a/init.d/openwrt/functions
+++ b/init.d/openwrt/functions
@@ -80,7 +80,7 @@ dnat6_target()
  # link local address can appear not immediately after ifup
  
  # DNAT6_TARGET=- means attempt was made but address was not found (to avoid multiple re-attempts)
- [ "$DNAT6_TARGET" = '-' ] || {
+ [ -n "$DNAT6_TARGET" ] || {
     # no reason to query if its down
     network_is_up lan || return
 
diff --git a/init.d/sysv/functions b/init.d/sysv/functions
index 280cb4f..6052cf8 100644
--- a/init.d/sysv/functions
+++ b/init.d/sysv/functions
@@ -105,7 +105,7 @@ dnat6_target()
 	# link local address can appear not immediately after ifup
 	
 	# DNAT6_TARGET=- means attempt was made but address was not found (to avoid multiple re-attempts)
-	[ "$DNAT6_TARGET" = '-' ] || {
+	[ -n "$DNAT6_TARGET" ] || {
 		local ct=0
 		while
 			DNAT6_TARGET=$(get_ipv6_linklocal $IFACE_LAN)