diff --git a/nse_nsock.cc b/nse_nsock.cc
index 254a8d2..71148f1 100644
--- a/nse_nsock.cc
+++ b/nse_nsock.cc
@@ -40,6 +40,8 @@ enum {
 #define THREAD_I  1 /* The thread that yielded */
 #define BUFFER_I  2 /* Location of Userdata Buffer */
 
+#define PCAP_IODS "pcap_iods" /* NSOCK_SOCKET metatable key */
+
 extern NmapOps o;
 
 typedef struct nse_nsock_udata
@@ -851,8 +853,15 @@ static int l_close (lua_State *L)
 static int nsock_gc (lua_State *L)
 {
   nse_nsock_udata *nu = check_nsock_udata(L, 1);
-  if (nu->nsiod)
+  if (nu->nsiod) {
+    lua_getmetatable(L, 1);
+    lua_getfield(L, -1, PCAP_IODS);
+    lua_pushvalue(L,1);
+    lua_pushnil(L);
+    lua_rawset(L,-3);
+    lua_pop(L, 2);
     return l_close(L);
+  }
   return 0;
 }
 
@@ -913,6 +922,7 @@ static int l_pcap_open (lua_State *L)
   nsock_iod *nsiod = (nsock_iod *) lua_touserdata(L, -1);
   if (nsiod == NULL) /* does not exist */
   {
+    lua_pop(L, 1); /* the nonexistant socket */
     nsiod = (nsock_iod *) lua_newuserdata(L, sizeof(nsock_iod));
     lua_pushvalue(L, PCAP_SOCKET);
     lua_setmetatable(L, -2);
@@ -924,12 +934,17 @@ static int l_pcap_open (lua_State *L)
     lua_pushvalue(L, -2); /* the pcap socket nsiod */
     lua_pushboolean(L, 1); /* dummy variable */
     lua_rawset(L, -3);
-    lua_pop(L, 1); /* the socket user value */
     char *e = nsock_pcap_open(nsp, *nsiod, lua_tostring(L, 6), snaplen,
         lua_toboolean(L, 4), bpf);
     if (e)
       luaL_error(L, "%s", e);
   }
+  lua_getmetatable(L, 1);
+  lua_getfield(L, -1, PCAP_IODS);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, -4);
+  lua_rawset(L, -3); /* NSOCK_SOCKET[PCAP_IODS][this]=pcap_nsiod */
+  lua_pop(L, 3);
   nu->nsiod = *nsiod;
   nu->is_pcap = 1;
   return 0;
@@ -1025,7 +1040,7 @@ LUALIB_API int luaopen_nsock (lua_State *L)
   lua_pushcclosure(L, nsock_gc, 6);
   lua_setfield(L, -2, "__gc");
   lua_newtable(L);
-  lua_setfield(L, -2, "__metatable");  /* protect metatable */
+  lua_setfield(L, -2, PCAP_IODS);
   lua_pop(L, 1); /* NSOCK_SOCKET */
 
   /* Create the nsock pcap metatable */