diff --git a/packages/ProbLog/problog/flags.yap b/packages/ProbLog/problog/flags.yap
index 5ecd9a21a..a6485a159 100644
--- a/packages/ProbLog/problog/flags.yap
+++ b/packages/ProbLog/problog/flags.yap
@@ -214,9 +214,9 @@
                          problog_flag/2]).
 
 
-:-ensure_loaded(gflags).
-:-ensure_loaded(os).
-:-ensure_loaded(logger).
+:- use_module(gflags).
+:- use_module(os).
+:- use_module(logger).
 
 problog_define_flag(Flag, Type, Description, DefaultValue):-
   flag_define(Flag, Type, DefaultValue, Description).
diff --git a/packages/ProbLog/problog/gflags.yap b/packages/ProbLog/problog/gflags.yap
index 5d8ea1d74..872f42eef 100644
--- a/packages/ProbLog/problog/gflags.yap
+++ b/packages/ProbLog/problog/gflags.yap
@@ -245,8 +245,8 @@
                  flag_get/2,
                  flags_reset/0]).
 
-:-ensure_loaded(library(lists)).
-:-ensure_loaded(library(system)). % for file operations
+:- use_module(library(lists)).
+:- use_module(library(system)). % for file operations
 
 flag_define(Flag, Type, DefaultValue, Message):-
   flag_define(Flag, general, Type, DefaultValue, flags:true, Message).