diff --git a/test/test_mandatory.py b/test/test_mandatory.py
index 6172c2a..1010256 100644
--- a/test/test_mandatory.py
+++ b/test/test_mandatory.py
@@ -2,7 +2,7 @@ import autopath
 
 #from py.test import raises
 from tiramisu.config import Config, mandatory_warnings
-from tiramisu.option import StrOption, OptionDescription
+from tiramisu.option import StrOption, OptionDescription, UnicodeOption
 from tiramisu.error import PropertiesOptionError
 
 
@@ -11,7 +11,7 @@ def make_description():
                           properties=('mandatory', ))
     stroption1 = StrOption('str1', 'Test string option',
                            properties=('mandatory', ))
-    stroption2 = StrOption('str2', 'Test string option',
+    stroption2 = UnicodeOption('unicode2', 'Test string option',
                            properties=('mandatory', ))
     stroption3 = StrOption('str3', 'Test string option', multi=True,
                            properties=('mandatory', ))
@@ -42,9 +42,9 @@ def test_mandatory_rw():
     setting = config.cfgimpl_get_settings()
     setting.read_write()
     #not mandatory in rw
-    config.str2
-    config.str2 = 'yes'
-    assert config.str2 == 'yes'
+    config.str1
+    config.str1 = 'yes'
+    assert config.str1 == 'yes'
 
 
 def test_mandatory_default():
@@ -180,6 +180,29 @@ def test_mandatory_disabled():
     assert prop == ['disabled', 'mandatory']
 
 
+def test_mandatory_unicode():
+    descr = make_description()
+    config = Config(descr)
+    setting = config.cfgimpl_get_settings()
+    config.unicode2
+    setting.read_only()
+    prop = []
+    try:
+        config.unicode2
+    except PropertiesOptionError, err:
+        prop = err.proptype
+    assert prop == ['mandatory']
+    setting.read_write()
+    config.unicode2 = u''
+    setting.read_only()
+    prop = []
+    try:
+        config.unicode2
+    except PropertiesOptionError, err:
+        prop = err.proptype
+    assert prop == ['mandatory']
+
+
 def test_mandatory_warnings_ro():
     descr = make_description()
     config = Config(descr)
@@ -192,11 +215,11 @@ def test_mandatory_warnings_ro():
     except PropertiesOptionError, err:
         proc = err.proptype
     assert proc == ['mandatory']
-    assert list(mandatory_warnings(config)) == ['str', 'str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str', 'str1', 'unicode2', 'str3']
     setting.read_write()
     config.str = 'a'
     setting.read_only()
-    assert list(mandatory_warnings(config)) == ['str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str1', 'unicode2', 'str3']
 
 
 def test_mandatory_warnings_rw():
@@ -206,9 +229,9 @@ def test_mandatory_warnings_rw():
     setting = config.cfgimpl_get_settings()
     setting.read_write()
     config.str
-    assert list(mandatory_warnings(config)) == ['str', 'str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str', 'str1', 'unicode2', 'str3']
     config.str = 'a'
-    assert list(mandatory_warnings(config)) == ['str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str1', 'unicode2', 'str3']
 
 
 def test_mandatory_warnings_disabled():
@@ -218,9 +241,9 @@ def test_mandatory_warnings_disabled():
     setting = config.cfgimpl_get_settings()
     setting.read_write()
     config.str
-    assert list(mandatory_warnings(config)) == ['str', 'str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str', 'str1', 'unicode2', 'str3']
     setting.add_property('disabled', descr.str)
-    assert list(mandatory_warnings(config)) == ['str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str1', 'unicode2', 'str3']
 
 
 def test_mandatory_warnings_frozen():
@@ -230,7 +253,7 @@ def test_mandatory_warnings_frozen():
     setting = config.cfgimpl_get_settings()
     setting.read_write()
     config.str
-    assert list(mandatory_warnings(config)) == ['str', 'str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str', 'str1', 'unicode2', 'str3']
     setting.add_property('frozen', descr.str)
     setting.read_only()
-    assert list(mandatory_warnings(config)) == ['str', 'str1', 'str2', 'str3']
+    assert list(mandatory_warnings(config)) == ['str', 'str1', 'unicode2', 'str3']
diff --git a/tiramisu/option.py b/tiramisu/option.py
index d410fc9..cad39f9 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -79,6 +79,7 @@ class Option(BaseInformation):
     __slots__ = ('_name', '_requires', '_multi', '_validator', '_default_multi',
                  '_default', '_properties', '_callback', '_multitype',
                  '_master_slaves', '_consistencies', '_empty')
+    _empty = ''
 
     def __init__(self, name, doc, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
@@ -110,7 +111,6 @@ class Option(BaseInformation):
         validate_requires_arg(requires, self._name)
         self._requires = requires
         self._multi = multi
-        self._empty = ''
         self._consistencies = None
         if validator is not None:
             if type(validator) != FunctionType:
@@ -345,6 +345,7 @@ class StrOption(Option):
 class UnicodeOption(Option):
     __slots__ = ('opt_type')
     opt_type = 'unicode'
+    _empty = u''
 
     def _validate(self, value):
         return isinstance(value, unicode)