diff --git a/NEWS b/NEWS
index dfbb36451..7bf8994f2 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,9 @@ New in spot 2.3.2.dev (not yet released)
   - In autfilt, the options --sum(--sum-or) and --sum-and are
     implemented.
 
+  - In autfilt, the option --dualize is now available to obtain the dual
+    of any automaton.
+
   - genltl learned --spec-patterns as an alias for --dac-patterns; it
     also learned two new sets of LTL formulas under --hkrss-patterns
     (a.k.a. --liberouter-patterns) and --p-patterns
diff --git a/bin/autfilt.cc b/bin/autfilt.cc
index ce24b1c4f..5ecbf8a87 100644
--- a/bin/autfilt.cc
+++ b/bin/autfilt.cc
@@ -91,6 +91,7 @@ enum {
   OPT_DECOMPOSE_STRENGTH,
   OPT_DECOMPOSE_SCC,
   OPT_DESTUT,
+  OPT_DUALIZE,
   OPT_DNF_ACC,
   OPT_EDGES,
   OPT_EQUIVALENT_TO,
@@ -301,6 +302,8 @@ static const argp_option options[] =
       " (letters may be combined to combine more strengths in the output)", 0 },
     { "decompose-scc", OPT_DECOMPOSE_SCC, "N", 0, "keep only the Nth accepting"
       " SCC as accepting", 0 },
+    { "dualize", OPT_DUALIZE, nullptr, 0,
+      "dualize each automaton", 0 },
     { "exclusive-ap", OPT_EXCLUSIVE_AP, "AP,AP,...", 0,
       "if any of those APs occur in the automaton, restrict all edges to "
       "ensure two of them may not be true at the same time.  Use this option "
@@ -485,6 +488,7 @@ static bool opt_complement = false;
 static bool opt_complement_acc = false;
 static char* opt_decompose_strength = nullptr;
 static int opt_decompose_scc = -1;
+static bool opt_dualize = false;
 static spot::acc_cond::mark_t opt_mask_acc = 0U;
 static std::vector<bool> opt_keep_states = {};
 static unsigned int opt_keep_states_initial = 0;
@@ -572,6 +576,9 @@ parse_opt(int key, char* arg, struct argp_state*)
       opt_cnf_acc = true;
       break;
     case OPT_COMPLEMENT:
+      if (opt_dualize)
+        error(2, 0, "either --complement or --dualize options"
+                    " can be given, not both");
       opt_complement = true;
       break;
     case OPT_COMPLEMENT_ACC:
@@ -586,6 +593,12 @@ parse_opt(int key, char* arg, struct argp_state*)
     case OPT_DESTUT:
       opt_destut = true;
       break;
+    case OPT_DUALIZE:
+      if (opt_complement)
+        error(2, 0, "either --complement or --dualize options"
+                    " can be given, not both");
+      opt_dualize = true;
+      break;
     case OPT_DNF_ACC:
       opt_dnf_acc = true;
       opt_cnf_acc = false;
@@ -1249,6 +1262,9 @@ namespace
       if (opt_complement)
         aut = spot::dualize(ensure_deterministic(aut));
 
+      if (opt_dualize)
+        aut = spot::dualize(aut);
+
       aut = post.run(aut, nullptr);
 
       if (opt_gra)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index da132b2f2..dcdf3b65e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -232,6 +232,7 @@ TESTS_twa = \
   core/explpro3.test \
   core/explpro4.test \
   core/explsum.test \
+  core/dualize.test \
   core/tripprod.test \
   core/dupexp.test \
   core/exclusive-tgba.test \
diff --git a/tests/core/dualize.test b/tests/core/dualize.test
new file mode 100755
index 000000000..58ffa68d7
--- /dev/null
+++ b/tests/core/dualize.test
@@ -0,0 +1,67 @@
+#!/bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2017 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
+
+set -e
+
+cat >input1 <<EOF
+HOA: v1
+States: 4
+Start: 0
+AP: 2 "a" "b"
+acc-name: Buchi
+Acceptance: 3 Inf(0) & Inf(1) & Fin(2)
+properties: trans-labels explicit-labels trans-acc
+--BODY--
+State: 0
+[0] 1&2&3
+[1] 0&1
+State: 1
+[t] 1 {0}
+State: 2
+[t] 2 {1}
+State: 3
+[0] 2
+[!0&!1] 0 {2}
+--END--
+EOF
+
+cat >expected <<EOF
+HOA: v1
+States: 2
+Start: 0
+AP: 2 "a" "b"
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels trans-acc complete
+properties: deterministic
+--BODY--
+State: 0
+[t] 1
+State: 1
+[t] 1
+--END--
+EOF
+
+run 0 autfilt input1 --dualize --hoaf=t | tee stdout
+diff stdout expected
+rm input1 expected stdout