diff --git a/smmapdfw/lua_worker.c b/smmapdfw/lua_worker.c
index f3bdc3b..8d80b23 100644
--- a/smmapdfw/lua_worker.c
+++ b/smmapdfw/lua_worker.c
@@ -172,10 +172,9 @@ int lua_work(void *handle, void *work_handle, char *input, char *output) {
 
   res = lua_pcall(lwh->l, 1, 2, 0);
 
-  lua_output = (char*) lua_tostring(lwh->l, lua_gettop(lwh->l));
-  lua_pop(lwh->l, 1);
+  /* peek the result from the stack */
+  lua_output = (char*) lua_tostring(lwh->l, lua_gettop(lwh->l));   
   result = lua_tonumber(lwh->l, lua_gettop(lwh->l));
-  lua_pop(lwh->l, 1);
 
   if (0 != res) {
     syslog(LOG_ERR, "lua_work: error when calling entrypoint function: %d", res);
@@ -185,5 +184,8 @@ int lua_work(void *handle, void *work_handle, char *input, char *output) {
     snprintf(output, ANSWER_BUFSIZE, lua_output);
   }
 
+  /* remove the result from the stack */
+  lua_pop(lwh->l, 2);
+
   return result;
 }