diff --git a/modules/net/copper.lua b/modules/net/copper.lua
index fbd16ef..92de0ce 100644
--- a/modules/net/copper.lua
+++ b/modules/net/copper.lua
@@ -3,7 +3,10 @@ net.id = computer.address():sub(1,8)
 net.np = 4957
 net.tm = {}
 function net.send(id,po,msg) -- id, port, message
- event.push("sendmsg",id,po,msg)
+ if id and po and msg then
+  event.push("sendmsg",id,po,msg)
+ else return false
+ end
 end
 if cdlib and relib then
 spawn("copperd",function() print(pcall(function ()
@@ -38,15 +41,17 @@ spawn("copperd",function() print(pcall(function ()
      event.push("net_rmsg",src,data)
      local pd = relib.decode(data)
      if pd then
-      if pd.pt == 1 then
-       event.push("net_msg",src,pd.port,pd.msg)
-       pd.pt = 2
-       pd.nid = src
-       pd.lt = 0
-       pd.msg = ""
-       ps[pd.pid] = pd
-      elseif pd.pt == 2 then
-       ps[pd.pid] = nil
+      if pd.port and pd.pid and pd.at and pd.pt and pd.msg then
+       if pd.pt == 1 then
+        event.push("net_msg",src,pd.port,pd.msg)
+        pd.pt = 2
+        pd.nid = src
+        pd.lt = 0
+        pd.msg = ""
+        ps[pd.pid] = pd
+       elseif pd.pt == 2 then
+        ps[pd.pid] = nil
+       end
       end
      end
     else