diff --git a/addons/project/__init__.py b/addons/project/__init__.py
index a983dc5d67a..e5493f8675a 100644
--- a/addons/project/__init__.py
+++ b/addons/project/__init__.py
@@ -7,6 +7,8 @@ from . import report
 from . import wizard
 from . import populate
 
+from odoo.tools.sql import create_index
+
 
 def _check_exists_collaborators_for_project_sharing(env):
     """ Check if it exists at least a collaborator in a shared project
@@ -21,3 +23,13 @@ def _check_exists_collaborators_for_project_sharing(env):
 
 def _project_post_init(env):
     _check_exists_collaborators_for_project_sharing(env)
+
+    # Index to improve the performance of burndown chart.
+    project_task_stage_field_id = env['ir.model.fields']._get_ids('project.task').get('stage_id')
+    create_index(
+        env.cr,
+        'mail_tracking_value_mail_message_id_old_value_integer_task_stage',
+        env['mail.tracking.value']._table,
+        ['mail_message_id', 'old_value_integer'],
+        where=f'field={project_task_stage_field_id}'
+    )
diff --git a/addons/project/models/__init__.py b/addons/project/models/__init__.py
index 3f3151245a2..1a600154490 100644
--- a/addons/project/models/__init__.py
+++ b/addons/project/models/__init__.py
@@ -2,6 +2,7 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from . import analytic_account
+from . import mail_message
 from . import project_milestone
 from . import project_project_stage
 from . import project_task_recurrence
diff --git a/addons/project/models/mail_message.py b/addons/project/models/mail_message.py
new file mode 100644
index 00000000000..009564854f3
--- /dev/null
+++ b/addons/project/models/mail_message.py
@@ -0,0 +1,18 @@
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import models
+from odoo.tools.sql import create_index
+
+
+class MailMessage(models.Model):
+    _inherit = 'mail.message'
+
+    def init(self):
+        super().init()
+        create_index(
+            self._cr,
+            'mail_message_date_res_id_id_for_burndown_chart',
+            self._table,
+            ['date', 'res_id', 'id'],
+            where="model='project.task' AND message_type='notification'"
+        )