diff --git a/mod/box/box_lua.m b/mod/box/box_lua.m
index 28add972b21257aa6f321ec60cd086a81f73ae65..30e18c86e2c74204b02a98ad32eaec32c0cf84af 100644
--- a/mod/box/box_lua.m
+++ b/mod/box/box_lua.m
@@ -642,6 +642,10 @@ static int lbox_process(lua_State *L)
 		rw_callback(op, &req);
 	} @finally {
 		fiber->mod_data.txn = old_txn;
+		/*
+		 * This only works as long as port_lua doesn't
+		 * use fiber->cleanup and fiber->gc_pool.
+		 */
 		ptruncate(fiber->gc_pool, allocated_size);
 	}
 	return lua_gettop(L) - top;
diff --git a/mod/box/port.m b/mod/box/port.m
index fe6c08f1a3fb4d6fc1245eeff9abc8b1451be68e..c0af5c5fdb38a1c5687d72abd9a704f96762ea2a 100644
--- a/mod/box/port.m
+++ b/mod/box/port.m
@@ -28,9 +28,8 @@
  */
 #include "port.h"
 #include <pickle.h>
+#include <fiber.h>
 #include <tarantool_lua.h>
-#include "request.h"
-#include "txn.h"
 #include "tuple.h"
 #include "box_lua.h"
 #include "lua.h"