diff --git a/lns.lua b/lns.lua
index 714be45..5a40752 100644
--- a/lns.lua
+++ b/lns.lua
@@ -15,7 +15,7 @@ function lns_lookup(hostname)
         lns_server_id = rednet.lookup("lns", lns_server)
         if lns_server_id == nil then
             io.write("LNS Server not found!\n")
-            return
+            return nil
         end
     end
 
@@ -52,9 +52,9 @@ if action == "lookup" then
     end
 
     local id = lns_lookup(hostname)
-    cache[hostname] = id
     if id ~= nil then
         io.write(id)
+        cache[hostname] = id
     end
 
 elseif action == "clear" then