diff --git a/rc.lua b/rc.lua
index a4d54bb..e9a1037 100644
--- a/rc.lua
+++ b/rc.lua
@@ -99,7 +99,9 @@ awful.layout.layouts = {
 
 function restart()
  for k,v in pairs(zombies) do
-  awful.spawn.easy_async(string.format("kill %d",v))
+  if type(v) == "number" then
+   awful.spawn.easy_async(string.format("kill %d",v))
+  end
  end
  awesome.restart()
 end