diff --git a/addons/project/models/project_task.py b/addons/project/models/project_task.py
index 312b1d47bf0..69234e827d7 100644
--- a/addons/project/models/project_task.py
+++ b/addons/project/models/project_task.py
@@ -150,7 +150,7 @@ class Task(models.Model):
     date_end = fields.Datetime(string='Ending Date', index=True, copy=False)
     date_assign = fields.Datetime(string='Assigning Date', copy=False, readonly=True,
         help="Date on which this task was last assigned (or unassigned). Based on this, you can get statistics on the time it usually takes to assign tasks.")
-    date_deadline = fields.Datetime(string='Deadline', index=True, copy=False, tracking=True)
+    date_deadline = fields.Datetime(string='Deadline', index=True, tracking=True)
 
     date_last_stage_update = fields.Datetime(string='Last Stage Update',
         index=True,
diff --git a/addons/project/tests/test_task_dependencies.py b/addons/project/tests/test_task_dependencies.py
index b52647ae20b..d3be6c85ef3 100644
--- a/addons/project/tests/test_task_dependencies.py
+++ b/addons/project/tests/test_task_dependencies.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from odoo.fields import Command
+from odoo.fields import Command, Datetime
 from odoo.exceptions import ValidationError
 from odoo.tests import tagged
 
@@ -126,6 +126,7 @@ class TestTaskDependencies(TestProjectCommon):
     def test_duplicate_project_with_task_dependencies(self):
         self.project_pigs.allow_task_dependencies = True
         self.task_1.depend_on_ids = self.task_2
+        self.task_1.date_deadline = Datetime.now()
         pigs_copy = self.project_pigs.copy()
 
         task1_copy = pigs_copy.task_ids.filtered(lambda t: t.name == 'Pigs UserTask')
@@ -136,6 +137,7 @@ class TestTaskDependencies(TestProjectCommon):
 
         self.assertEqual(task1_copy.depend_on_ids.ids, [task2_copy.id],
                          "Copy should only create a relation between both copy if they are both part of the project")
+        self.assertEqual(task1_copy.date_deadline, self.task_1.date_deadline, "date_deadline should be copied")
 
         task1_copy.depend_on_ids = self.task_1