diff --git a/tests/test_config_api.py b/tests/test_config_api.py
index 2bfa337..27036ee 100644
--- a/tests/test_config_api.py
+++ b/tests/test_config_api.py
@@ -323,13 +323,10 @@ async def test_filename(config_type):
         await cfg.option('a').value.set('/tmp')
         await cfg.option('a').value.set('/tmp/')
         await cfg.option('a').value.set('/tmp/text.txt')
-        await cfg.option('a').value.set('tmp')
-        await cfg.option('a').value.set('tmp/')
-        await cfg.option('a').value.set('tmp/text.txt')
+        await cfg.option('a').value.set('/tmp/with space.txt')
+        await cfg.option('a').value.set('/tmp/with$.txt')
         with pytest.raises(ValueError):
-            await cfg.option('a').value.set('/tmp/with space.txt')
-        with pytest.raises(ValueError):
-            await cfg.option('a').value.set('/tmp/with$.txt')
+            await cfg.option('a').value.set('not starts with /')
     assert not await list_sessions()
 
 
diff --git a/tiramisu/option/filenameoption.py b/tiramisu/option/filenameoption.py
index ad0d2cb..7abdc0e 100644
--- a/tiramisu/option/filenameoption.py
+++ b/tiramisu/option/filenameoption.py
@@ -21,11 +21,17 @@
 import re
 
 from ..i18n import _
-from .stroption import RegexpOption
+from .stroption import StrOption
 
 
-class FilenameOption(RegexpOption):
+class FilenameOption(StrOption):
     __slots__ = tuple()
-    _regexp = re.compile(r"^[a-zA-Z0-9\-\._~/+]+$")
     _type = 'filename'
     _display_name = _('file name')
+
+    def validate(self,
+                 value: str,
+                 ) -> None:
+        super().validate(value)
+        if not value.startswith('/'):
+            raise ValueError(_('must starts with "/"'))