diff --git a/test/test_parsing_group.py b/test/test_parsing_group.py
index 934d3ef..373aba2 100644
--- a/test/test_parsing_group.py
+++ b/test/test_parsing_group.py
@@ -288,3 +288,99 @@ def test_values_with_master_disabled():
     cfg.ip_admin_eth0.netmask_admin_eth0 = ["192.168.230.145"]
     cfg.cfgimpl_get_settings()[netmask_admin_eth0].append('disabled')
     cfg.ip_admin_eth0.ip_admin_eth0.append('192.168.230.43')
+
+
+def test_multi_insert():
+    var = StrOption('var', '', ['ok'], multi=True)
+    od = OptionDescription('od', '', [var])
+    c = Config(od)
+    c.read_write()
+    assert c.var == ['ok']
+    assert c.getowner("var") == owners.default
+    c.var.insert(0, 'nok')
+    assert c.var == ['nok', 'ok']
+    assert c.getowner("var") != owners.default
+
+
+def test_multi_insert_master():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('toto', '', [interface1])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    raises(SlaveError, "cfg.ip_admin_eth0.ip_admin_eth0.insert(0, 'nok')")
+    raises(SlaveError, "cfg.ip_admin_eth0.netmask_admin_eth0.insert(0, 'nok')")
+
+
+def test_multi_sort():
+    var = StrOption('var', '', ['ok', 'nok'], multi=True)
+    od = OptionDescription('od', '', [var])
+    c = Config(od)
+    c.read_write()
+    assert c.var == ['ok', 'nok']
+    assert c.getowner("var") == owners.default
+    c.var.sort()
+    assert c.var == ['nok', 'ok']
+    assert c.getowner("var") != owners.default
+
+
+def test_multi_sort_master():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('toto', '', [interface1])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    raises(SlaveError, "cfg.ip_admin_eth0.ip_admin_eth0.sort()")
+    raises(SlaveError, "cfg.ip_admin_eth0.netmask_admin_eth0.sort()")
+
+
+def test_multi_reverse():
+    var = StrOption('var', '', ['ok', 'nok'], multi=True)
+    od = OptionDescription('od', '', [var])
+    c = Config(od)
+    c.read_write()
+    assert c.var == ['ok', 'nok']
+    assert c.getowner("var") == owners.default
+    c.var.reverse()
+    assert c.var == ['nok', 'ok']
+    assert c.getowner("var") != owners.default
+
+
+def test_multi_reverse_master():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('toto', '', [interface1])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    raises(SlaveError, "cfg.ip_admin_eth0.ip_admin_eth0.reverse()")
+    raises(SlaveError, "cfg.ip_admin_eth0.netmask_admin_eth0.reverse()")
+
+
+def test_multi_extend():
+    var = StrOption('var', '', ['ok', 'nok'], multi=True)
+    od = OptionDescription('od', '', [var])
+    c = Config(od)
+    c.read_write()
+    assert c.var == ['ok', 'nok']
+    assert c.getowner("var") == owners.default
+    c.var.extend(['pok'])
+    assert c.var == ['ok', 'nok', 'pok']
+    assert c.getowner("var") != owners.default
+
+
+def test_multi_extend_master():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip réseau autorisé", multi=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-réseau", multi=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    maconfig = OptionDescription('toto', '', [interface1])
+    cfg = Config(maconfig)
+    cfg.read_write()
+    raises(SlaveError, "cfg.ip_admin_eth0.ip_admin_eth0.extend(['ok'])")
+    raises(SlaveError, "cfg.ip_admin_eth0.netmask_admin_eth0.extend(['ok'])")
diff --git a/tiramisu/value.py b/tiramisu/value.py
index 0f07759..11d23cd 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -325,6 +325,38 @@ class Multi(list):
                     values.getitem(slave, validate_properties=False).append(
                         dvalue, force=True)
 
+    def sort(self, cmp=None, key=None, reverse=False):
+        if self.opt.impl_get_multitype() in [multitypes.slave,
+                                             multitypes.master]:
+            raise SlaveError(_("cannot sort multi option {0} if master or slave"
+                               "").format(self.opt._name))
+        self.context.cfgimpl_get_values()._setvalue(self.opt, self)
+        super(Multi, self).sort(cmp=cmp, key=key, reverse=reverse)
+
+    def reverse(self):
+        if self.opt.impl_get_multitype() in [multitypes.slave,
+                                             multitypes.master]:
+            raise SlaveError(_("cannot reverse multi option {0} if master or "
+                               "slave").format(self.opt._name))
+        self.context.cfgimpl_get_values()._setvalue(self.opt, self)
+        super(Multi, self).reverse()
+
+    def insert(self, index, obj):
+        if self.opt.impl_get_multitype() in [multitypes.slave,
+                                             multitypes.master]:
+            raise SlaveError(_("cannot insert multi option {0} if master or "
+                               "slave").format(self.opt._name))
+        self.context.cfgimpl_get_values()._setvalue(self.opt, self)
+        super(Multi, self).insert(index, obj)
+
+    def extend(self, iterable):
+        if self.opt.impl_get_multitype() in [multitypes.slave,
+                                             multitypes.master]:
+            raise SlaveError(_("cannot extend multi option {0} if master or "
+                               "slave").format(self.opt._name))
+        self.context.cfgimpl_get_values()._setvalue(self.opt, self)
+        super(Multi, self).extend(iterable)
+
     def _validate(self, value):
         if value is not None and not self.opt._validate(value):
             raise ValueError(_("invalid value {0} "