diff --git a/project_average_acceptable_time/__manifest__.py b/project_average_acceptable_time/__manifest__.py
index 51d373b..ac156a8 100644
--- a/project_average_acceptable_time/__manifest__.py
+++ b/project_average_acceptable_time/__manifest__.py
@@ -3,7 +3,7 @@
 
 {
     "name": "project_average_acceptable_time",
-    "version": "18.0.1.0.0",
+    "version": "18.0.1.1.0",
     "author": "Elabore",
     "website": "https://git.elabore.coop/elabore/project-tools",
     "maintainer": "Clément Thomas",
diff --git a/project_average_acceptable_time/controllers/custom_portal.py b/project_average_acceptable_time/controllers/custom_portal.py
index ff484d5..5cfa014 100644
--- a/project_average_acceptable_time/controllers/custom_portal.py
+++ b/project_average_acceptable_time/controllers/custom_portal.py
@@ -17,9 +17,12 @@ class CustomCustomerPortal(CustomerPortal):
         if post and request.httprequest.method == "POST":
             error, error_message = self.details_form_validate(post)
             if not error:
-                user = request.env.user
-                if user.default_project_id and post["average_acceptable_time"]:
-                    user.default_project_id.average_acceptable_time = post[
+                # sudo: a portal user has no write access at all on
+                # project.project, and no read access on its default project
+                # unless it follows it
+                project_sudo = request.env.user.sudo().default_project_id
+                if project_sudo and post.get("average_acceptable_time"):
+                    project_sudo.average_acceptable_time = post[
                         "average_acceptable_time"
                     ]
 
diff --git a/project_average_acceptable_time/views/portal_home_template.xml b/project_average_acceptable_time/views/portal_home_template.xml
index 0e6152b..d8beeb2 100644
--- a/project_average_acceptable_time/views/portal_home_template.xml
+++ b/project_average_acceptable_time/views/portal_home_template.xml
@@ -8,11 +8,19 @@
         priority="40"
     >
         <xpath expr="//div[@class='o_portal_my_details']" position="inside">
-            <hr class="mt-1 mb-0" />
-            <b>Average acceptable time</b>: <t
-                t-esc="user_id.default_project_id.average_acceptable_time"
-                t-options="{'widget': 'float_time'}"
+            <!-- sudo: a portal user cannot read its own default project
+                 unless it follows it (project.project_project_rule_portal) -->
+            <t
+                t-set="default_project_sudo"
+                t-value="user_id.sudo().default_project_id"
             />
+            <t t-if="default_project_sudo">
+                <hr class="mt-1 mb-0" />
+                <b>Average acceptable time</b>: <t
+                    t-esc="default_project_sudo.average_acceptable_time"
+                    t-options="{'widget': 'float_time'}"
+                />
+            </t>
         </xpath>
     </template>
 
@@ -34,7 +42,7 @@
                     type="text"
                     name="average_acceptable_time"
                     t-attf-class="form-control #{error.get('average_acceptable_time') and 'is-invalid' or ''}"
-                    t-att-value="average_acceptable_time or user_id.default_project_id.average_acceptable_time"
+                    t-att-value="average_acceptable_time or user_id.sudo().default_project_id.average_acceptable_time"
                     t-options="{'widget': 'float_time'}"
                 />
             </div>