diff --git a/luad.c b/luad.c
index 0be0ac6..1a9f0b3 100644
--- a/luad.c
+++ b/luad.c
@@ -118,6 +118,9 @@ int start_lua_child(lua_State *L,
         lua_seti(L, -2, i++);
         word = word_end + 1;
     }
+    if(! pathname) {
+        die("no script name received from client");
+    }
     lua_setglobal(L, "arg");
     int status = luaL_dofile(L, pathname);
     if (status) {