diff --git a/hr_payroll_attendance/__init__.py b/hr_payroll_attendance/__init__.py
index 0650744f..4e3ff034 100755
--- a/hr_payroll_attendance/__init__.py
+++ b/hr_payroll_attendance/__init__.py
@@ -1 +1,19 @@
 from . import models
+
+
+def attn_payroll_pre_init_hook(cr):
+    """
+    This module installs a Work Entry Type with code "ATTN"
+    If you have undergone a migration (either for this module
+    or even your own Payslip Work Entry lines with code "ATTN")
+    then the uniqueness constraint will prevent this module
+    from installing.
+    """
+    cr.execute("UPDATE hr_work_entry_type "
+               "SET code = 'ATTN-PRE-INSTALL' "
+               "WHERE code = 'ATTN';"
+               )
+    cr.execute("UPDATE hr_work_entry_type "
+               "SET code = 'ATTN_OT-PRE-INSTALL' "
+               "WHERE code = 'ATTN_OT';"
+               )
diff --git a/hr_payroll_attendance/__manifest__.py b/hr_payroll_attendance/__manifest__.py
index 6b18d0a3..3a1be326 100755
--- a/hr_payroll_attendance/__manifest__.py
+++ b/hr_payroll_attendance/__manifest__.py
@@ -17,4 +17,5 @@
         'hr_attendance',
         'hr_payroll_overtime',
     ],
+    'pre_init_hook': 'attn_payroll_pre_init_hook',
 }
diff --git a/hr_payroll_attendance/migrations/13.0.0.0.1/pre-migration.py b/hr_payroll_attendance/migrations/13.0.0.0.1/pre-migration.py
new file mode 100644
index 00000000..6c081185
--- /dev/null
+++ b/hr_payroll_attendance/migrations/13.0.0.0.1/pre-migration.py
@@ -0,0 +1,6 @@
+
+def migrate(cr, version):
+    # pre_init_hook script only runs on install,
+    # if you're coming from 12.0 we need the same change
+    from odoo.addons.hr_payroll_timesheet import attn_payroll_pre_init_hook
+    attn_payroll_pre_init_hook(cr)