diff --git a/.gitignore b/.gitignore
index c28cbd1..53205ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 *.pyc
 *.pyo
 *.orig
+.env
 /.tox
 /bin
 /include
diff --git a/CHANGES.rst b/CHANGES.rst
index bfe2a4c..9a397a7 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,6 +5,7 @@ Unreleased
 ----------
 
 * Use index=True when declaring language columns to be able to search efficiently on language fields.
+* Mark object with the translation property as modified when the property setter is called (bubenkoff)
 
 1.0.0
 -----
diff --git a/traduki/config.py b/traduki/config.py
index 2caf399..2fda5af 100644
--- a/traduki/config.py
+++ b/traduki/config.py
@@ -1,7 +1,13 @@
 """Configuration for i18n."""
 
-LANGUAGE_CALLBACK = lambda: 'en'
 
-LANGUAGE_CHAIN_CALLBACK = lambda: {'*': LANGUAGE_CALLBACK()}
+def LANGUAGE_CALLBACK():
+    """Current language callback."""
+    return 'en'
+
+
+def LANGUAGE_CHAIN_CALLBACK():
+    """Language chain callback."""
+    return {'*': LANGUAGE_CALLBACK()}
 
 LANGUAGES = ['en']
diff --git a/traduki/sqla.py b/traduki/sqla.py
index bd60353..f004670 100644
--- a/traduki/sqla.py
+++ b/traduki/sqla.py
@@ -10,7 +10,9 @@
 
 from sqlalchemy import Column, Integer, ForeignKey, UnicodeText
 from sqlalchemy.exc import ArgumentError
+from sqlalchemy.inspection import inspect
 from sqlalchemy.orm import relationship
+from sqlalchemy.orm.attributes import flag_modified
 from sqlalchemy.orm.interfaces import AttributeExtension
 from sqlalchemy.orm.properties import RelationshipProperty
 from sqlalchemy.sql import operators as oper, functions as func
@@ -134,6 +136,8 @@ def set(state, value, oldvalue, initiator):
             :param oldvalue: The current value.
             :param initiator: SQLAlchemy initiator (accessor).
             """
+            if state._strong_obj is not None:
+                flag_modified(state._strong_obj, inspect(state._strong_obj.__class__).primary_key[0].name)
             if value is None:
                 return None