diff --git a/mass_mailing_unique/README.rst b/mass_mailing_unique/README.rst
index c97cabcf..ea59209d 100644
--- a/mass_mailing_unique/README.rst
+++ b/mass_mailing_unique/README.rst
@@ -46,11 +46,6 @@ mass_mailing_unique%0Aversion:%20
 Credits
 =======
 
-Images
-------
-
-* Odoo Community Association: `Icon <https://github.com/OCA/maintainer-tools/blob/master/template/module/static/description/icon.svg>`_.
-
 Contributors
 ------------
 
diff --git a/mass_mailing_unique/__init__.py b/mass_mailing_unique/__init__.py
index b434bd97..baa4dd41 100644
--- a/mass_mailing_unique/__init__.py
+++ b/mass_mailing_unique/__init__.py
@@ -2,43 +2,5 @@
 # © 2015 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 
-from openerp import _
-from openerp.exceptions import ValidationError
 from . import models
-
-
-def require_no_duplicates(cr):
-    """Make sure there are no duplicates before installing the module.
-
-    If you define a unique key in Odoo that cannot be applied, Odoo will log a
-    warning and install the module without that constraint. Since this module
-    is useless without those constraints, we check here if all will work before
-    installing, and provide a user-friendly message in case of failure.
-    """
-    errors = list()
-
-    # Search for duplicates in emails
-    cr.execute("""SELECT c.email, l.name AS list, COUNT(c.id) AS duplicates
-                  FROM
-                    mail_mass_mailing_contact AS c
-                    INNER JOIN mail_mass_mailing_list AS l ON c.list_id = l.id
-                  GROUP BY l.name, l.id, c.email
-                  HAVING COUNT(c.id) > 1""")
-    for result in cr.dictfetchall():
-        errors.append(
-            _("%(email)s appears %(duplicates)d times in list %(list)s") %
-            result)
-
-    # Search for duplicates in list's name
-    cr.execute("""SELECT name, COUNT(id) as duplicates
-                  FROM mail_mass_mailing_list
-                  GROUP BY name
-                  HAVING COUNT(id) > 1""")
-    for result in cr.dictfetchall():
-        errors.append(
-            _("there are %(duplicates)d lists with name %(name)s") % result)
-
-    # Abort if duplicates are found
-    if errors:
-        raise ValidationError(
-            _("Fix this before installing: %s.") % ", ".join(errors))
+from .hooks import pre_init_hook
diff --git a/mass_mailing_unique/__openerp__.py b/mass_mailing_unique/__openerp__.py
index 30b87728..5b7917d5 100644
--- a/mass_mailing_unique/__openerp__.py
+++ b/mass_mailing_unique/__openerp__.py
@@ -12,7 +12,7 @@
     "license": "AGPL-3",
     "application": False,
     "installable": True,
-    "pre_init_hook": "require_no_duplicates",
+    "pre_init_hook": "pre_init_hook",
     "images": [
         "images/error-duplicated-email.png",
         "images/error-duplicated-list.png",
diff --git a/mass_mailing_unique/hooks.py b/mass_mailing_unique/hooks.py
new file mode 100644
index 00000000..7c8de0c9
--- /dev/null
+++ b/mass_mailing_unique/hooks.py
@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+# © 2015 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from openerp import _
+from openerp.exceptions import ValidationError
+
+
+def pre_init_hook(cr):
+    """Make sure there are no duplicates before installing the module.
+
+    If you define a unique key in Odoo that cannot be applied, Odoo will log a
+    warning and install the module without that constraint. Since this module
+    is useless without those constraints, we check here if all will work before
+    installing, and provide a user-friendly message in case of failure.
+    """
+    errors = list()
+
+    # Search for duplicates in emails
+    cr.execute("""SELECT c.email, l.name AS list, COUNT(c.id) AS duplicates
+                  FROM
+                    mail_mass_mailing_contact AS c
+                    INNER JOIN mail_mass_mailing_list AS l ON c.list_id = l.id
+                  GROUP BY l.name, l.id, c.email
+                  HAVING COUNT(c.id) > 1""")
+    for result in cr.dictfetchall():
+        errors.append(
+            _("%(email)s appears %(duplicates)d times in list %(list)s") %
+            result)
+
+    # Search for duplicates in list's name
+    cr.execute("""SELECT name, COUNT(id) as duplicates
+                  FROM mail_mass_mailing_list
+                  GROUP BY name
+                  HAVING COUNT(id) > 1""")
+    for result in cr.dictfetchall():
+        errors.append(
+            _("there are %(duplicates)d lists with name %(name)s") % result)
+
+    # Abort if duplicates are found
+    if errors:
+        raise ValidationError(
+            _("Fix this before installing: %s.") % ", ".join(errors))