diff --git a/patoolib/__init__.py b/patoolib/__init__.py
index 6acd893..b4c926d 100644
--- a/patoolib/__init__.py
+++ b/patoolib/__init__.py
@@ -238,8 +238,8 @@ def list_formats ():
                 print
             except util.PatoolError:
                 handlers = programs.get(None, programs.get(command))
-                print "   %8s: - (no program found; install one of %s)" % \
-                      (command, ", ".join(handlers))
+                print "   %8s: - (no program found; install %s)" % \
+                      (command, util.strlist_with_or(handlers))
     return 0
 
 
diff --git a/patoolib/util.py b/patoolib/util.py
index e6a7f61..6803c8e 100644
--- a/patoolib/util.py
+++ b/patoolib/util.py
@@ -120,3 +120,10 @@ def find_program (program):
     # XXX memoize result of this function
     path = os.environ['PATH']
     return find_executable(program, path=path)
+
+
+def strlist_with_or (list):
+    """Return comma separated string, and last entry appended with ' or '."""
+    if len(list) > 1:
+        return "%s or %s" % (", ".join(list[:-1]), list[-1])
+    return ", ".join(list)
diff --git a/tests/test_formats.py b/tests/test_formats.py
new file mode 100644
index 0000000..52326d1
--- /dev/null
+++ b/tests/test_formats.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2010 Bastian Kleineidam
+#
+# This program 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.
+#
+# This program 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/>.
+import unittest
+import patoolib
+
+class TestFormats (unittest.TestCase):
+
+    def test_list_formats (self):
+        patoolib.list_formats()