diff --git a/taiga/base/fields.py b/taiga/base/fields.py
index 69ce3868..63c7739a 100644
--- a/taiga/base/fields.py
+++ b/taiga/base/fields.py
@@ -55,9 +55,9 @@ class I18NJsonField(JsonField):
 
             if key in self.i18n_fields:
                 if isinstance(value, list):
-                    i18n_d[key] = [_(e) for e in value]
+                    i18n_d[key] = [e is not None and _(e) or e for e in value]
                 if isinstance(value, str):
-                    i18n_d[key] = _(value)
+                    i18n_d[key] = value is not None and _(value) or value
             else:
                 i18n_d[key] = value