diff -rdu lua-5.1.3.orig/src/lbaselib.c lua-5.1.3/src/lbaselib.c
--- lua-5.1.3.orig/src/lbaselib.c	2008-02-12 16:43:49.000000000 +0000
+++ lua-5.1.3/src/lbaselib.c	2008-02-12 16:47:32.000000000 +0000
@@ -526,7 +526,7 @@
   status = lua_resume(co, narg);
   if (status == 0 || status == LUA_YIELD) {
     int nres = lua_gettop(co);
-    if (!lua_checkstack(L, nres))
+    if (!lua_checkstack(L, nres + 1))
       luaL_error(L, "too many results to resume");
     lua_xmove(co, L, nres);  /* move yielded values */
     return nres;