diff --git a/files/www/cgi-bin/setup b/files/www/cgi-bin/setup
index dfc51c14..86b53c5e 100755
--- a/files/www/cgi-bin/setup
+++ b/files/www/cgi-bin/setup
@@ -682,7 +682,7 @@ if parms.button_save then
         end
     end
     if wifi3_enable == "1" then
-        if #wifi3_key < 8 or #wifi3_key > 64 then
+        if #wifi3_key ~= 0 and (#wifi3_key < 8 or #wifi3_key > 64) then
             err("WAN Wifi Client Password must be between 8 and 64 characters")
         end
         if wifi3_key:match("'") or wifi3_ssid:match("'") then