diff --git a/NEWS b/NEWS
index 3d275ab71..4c91d9047 100644
--- a/NEWS
+++ b/NEWS
@@ -37,6 +37,9 @@ New in spot 1.99.7a (not yet released)
     "autfilt --complement --tgba" will likely output a
     nondeterministic TGBA.
 
+  * autfilt has a new option, --included-in, to filter automata whose
+    language are included in the language of a given automaton.
+
   Library:
 
   * Building products with different dictionaries now raise an
diff --git a/bin/autfilt.cc b/bin/autfilt.cc
index 8fde37b84..fc3b162f2 100644
--- a/bin/autfilt.cc
+++ b/bin/autfilt.cc
@@ -82,6 +82,7 @@ enum {
   OPT_EXCLUSIVE_AP,
   OPT_GENERIC,
   OPT_INSTUT,
+  OPT_INCLUDED_IN,
   OPT_INTERSECT,
   OPT_IS_COMPLETE,
   OPT_IS_DETERMINISTIC,
@@ -206,6 +207,9 @@ static const argp_option options[] =
     { "intersect", OPT_INTERSECT, "FILENAME", 0,
       "keep automata whose languages have an non-empty intersection with"
       " the automaton from FILENAME", 0 },
+    { "included-in", OPT_INCLUDED_IN, "FILENAME", 0,
+      "keep automata whose languages are included in that of the "
+      "automaton from FILENAME", 0 },
     { "invert-match", 'v', nullptr, 0, "select non-matching automata", 0 },
     { "states", OPT_STATES, "RANGE", 0,
       "keep automata whose number of states are in RANGE", 0 },
@@ -259,6 +263,7 @@ static struct opt_t
   spot::twa_graph_ptr product_and = nullptr;
   spot::twa_graph_ptr product_or = nullptr;
   spot::twa_graph_ptr intersect = nullptr;
+  spot::twa_graph_ptr included_in = nullptr;
   spot::twa_graph_ptr are_isomorphic = nullptr;
   std::unique_ptr<spot::isomorphism_checker>
                          isomorphism_checker = nullptr;
@@ -299,6 +304,18 @@ static bool opt_rem_unreach = false;
 static bool opt_sep_sets = false;
 static const char* opt_sat_minimize = nullptr;
 
+static spot::twa_graph_ptr
+ensure_deterministic(const spot::twa_graph_ptr& aut)
+{
+  if (spot::is_deterministic(aut))
+    return aut;
+  spot::postprocessor p;
+  p.set_type(spot::postprocessor::Generic);
+  p.set_pref(spot::postprocessor::Deterministic);
+  p.set_level(level);
+  return p.run(aut);
+}
+
 static int
 parse_opt(int key, char* arg, struct argp_state*)
 {
@@ -371,6 +388,16 @@ parse_opt(int key, char* arg, struct argp_state*)
       else
 	error(2, 0, "unknown argument for --instut: %s", arg);
       break;
+    case OPT_INCLUDED_IN:
+      {
+	auto aut = ensure_deterministic(read_automaton(arg, opt->dict));
+	aut = spot::dtwa_complement(aut);
+	if (!opt->included_in)
+	  opt->included_in = aut;
+	else
+	  opt->included_in = spot::product_or(opt->included_in, aut);
+      }
+      break;
     case OPT_INTERSECT:
       opt->intersect = read_automaton(arg, opt->dict);
       break;
@@ -598,6 +625,8 @@ namespace
 	matched &= aut->is_empty();
       if (opt->intersect)
 	matched &= !spot::product(aut, opt->intersect)->is_empty();
+      if (opt->included_in)
+	matched &= spot::product(aut, opt->included_in)->is_empty();
 
       // Drop or keep matched automata depending on the --invert option
       if (matched == opt_invert)
@@ -648,18 +677,7 @@ namespace
 	}
 
       if (opt_complement)
-	{
-	  if (!spot::is_deterministic(aut))
-	    {
-	      // let's determinize that automaton
-	      spot::postprocessor p;
-	      p.set_type(spot::postprocessor::Generic);
-	      p.set_pref(spot::postprocessor::Deterministic);
-	      p.set_level(level);
-	      aut = p.run(aut);
-	    }
-	  aut = spot::dtwa_complement(aut);
-	}
+	aut = spot::dtwa_complement(ensure_deterministic(aut));
 
       aut = post.run(aut, nullptr);
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index eafc97a7c..d4b68775c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -255,6 +255,7 @@ TESTS_twa = \
   core/randaut.test \
   core/randtgba.test \
   core/isomorph.test \
+  core/included.test \
   core/uniq.test \
   core/safra.test \
   core/sbacc.test \
diff --git a/tests/core/included.test b/tests/core/included.test
new file mode 100755
index 000000000..114ee0609
--- /dev/null
+++ b/tests/core/included.test
@@ -0,0 +1,39 @@
+#! /bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2016 Laboratoire de Recherche et Développement
+# de l'Epita (LRDE).
+#
+# This file is part of Spot, a model checking library.
+#
+# Spot is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# Spot is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+. ./defs || exit 1
+
+set -x
+
+ltl2tgba 'G(a&b)' > gab.hoa
+ltl2tgba 'Ga' > ga.hoa
+ltl2tgba 'false' > false.hoa
+
+ltl2tgba FGa > fga.hoa
+ltl2tgba FGb > fgb.hoa
+ltl2tgba GFa > gfa.hoa
+
+run 0 autfilt -q fga.hoa --included-in gfa.hoa
+run 0 autfilt -q fga.hoa --included-in fga.hoa
+run 1 autfilt -q gfa.hoa --included-in fga.hoa
+run 0 autfilt -q gab.hoa --included-in fga.hoa --included-in fgb.hoa
+run 1 autfilt -q ga.hoa --included-in fga.hoa --included-in fgb.hoa
+run 0 autfilt -q false.hoa --included-in fga.hoa