diff --git a/runbot_merge/changelog/2022-06/branch.md b/runbot_merge/changelog/2022-06/branch.md
new file mode 100644
index 00000000..6c7c302b
--- /dev/null
+++ b/runbot_merge/changelog/2022-06/branch.md
@@ -0,0 +1,4 @@
+IMP: automatically close PRs when their target branch is deactivated
+
+Leave a message on the PRs to explain, such PRs should also be reopen-able if
+the users wants to retarget them.
diff --git a/runbot_merge/controllers/__init__.py b/runbot_merge/controllers/__init__.py
index 3b0b02c0..7e134af3 100644
--- a/runbot_merge/controllers/__init__.py
+++ b/runbot_merge/controllers/__init__.py
@@ -145,11 +145,11 @@ def handle_pr(env, event):
 
     message = None
     if not branch:
-        message = f"This PR targets the un-managed branch {r}:{b}, it can not be merged."
+        message = f"This PR targets the un-managed branch {r}:{b}, it needs to be retargeted before it can be merged."
         _logger.info("Ignoring event %s on PR %s#%d for un-managed branch %s",
                      event['action'], r, pr['number'], b)
     elif not branch.active:
-        message = f"This PR targets the disabled branch {r}:{b}, it can not be merged."
+        message = f"This PR targets the disabled branch {r}:{b}, it needs to be retargeted before it can be merged."
     if message and event['action'] not in ('synchronize', 'closed'):
         feedback(message=message)
 
diff --git a/runbot_merge/models/pull_requests.py b/runbot_merge/models/pull_requests.py
index 5ced85e1..33a087b6 100644
--- a/runbot_merge/models/pull_requests.py
+++ b/runbot_merge/models/pull_requests.py
@@ -249,6 +249,23 @@ class Branch(models.Model):
             self._table, ['name', 'project_id'])
         return res
 
+    @api.depends('active')
+    def _compute_display_name(self):
+        super()._compute_display_name()
+        for b in self.filtered(lambda b: not b.active):
+            b.display_name += ' (inactive)'
+
+    def write(self, vals):
+        super().write(vals)
+        if vals.get('active') is False:
+            self.env['runbot_merge.pull_requests.feedback'].create([{
+                'repository': pr.repository.id,
+                'pull_request': pr.number,
+                'close': True,
+                'message': f'{pr.ping()}the target branch {pr.target.name!r} has been disabled, closing this PR.',
+            } for pr in self.prs])
+        return True
+
     @api.depends('staging_ids.active')
     def _compute_active_staging(self):
         for b in self:
diff --git a/runbot_merge/tests/test_basic.py b/runbot_merge/tests/test_basic.py
index 5049fcda..f039b606 100644
--- a/runbot_merge/tests/test_basic.py
+++ b/runbot_merge/tests/test_basic.py
@@ -6,7 +6,7 @@ import time
 from unittest import mock
 
 import pytest
-from lxml import html
+from lxml import html, etree
 
 import odoo
 from utils import _simple_init, seen, re_matches, get_partner, Commit, pr_page, to_pr, part_of
@@ -26,21 +26,34 @@ def repo(env, project, make_repo, users, setreviewers):
 def test_trivial_flow(env, repo, page, users, config):
     # create base branch
     with repo:
-        m = repo.make_commit(None, "initial", None, tree={'a': 'some content'})
-        repo.make_ref('heads/master', m)
+        [m] = repo.make_commits(None, Commit("initial", tree={'a': 'some content'}), ref='heads/master')
 
         # create PR with 2 commits
-        c0 = repo.make_commit(m, 'replace file contents', None, tree={'a': 'some other content'})
-        c1 = repo.make_commit(c0, 'add file', None, tree={'a': 'some other content', 'b': 'a second file'})
-        pr = repo.make_pr(title="gibberish", body="blahblah", target='master', head=c1,)
+        _, c1 = repo.make_commits(
+            m,
+            Commit('replace file contents', tree={'a': 'some other content'}),
+            Commit('add file', tree={'b': 'a second file'}),
+            ref='heads/other'
+        )
+        pr = repo.make_pr(title="gibberish", body="blahblah", target='master', head='other')
 
     pr_id = to_pr(env, pr)
     assert pr_id.state == 'opened'
     env.run_crons()
     assert pr.comments == [seen(env, pr, users)]
-    s = pr_page(page, pr).cssselect('.alert-info > ul > li')
+
+    pr_dashboard = pr_page(page, pr)
+    s = pr_dashboard.cssselect('.alert-info > ul > li')
     assert [it.get('class') for it in s] == ['fail', 'fail', ''],\
         "merge method unset, review missing, no CI"
+    assert dict(zip(
+        [e.text_content() for e in pr_dashboard.cssselect('dl.runbot-merge-fields dt')],
+        [e.text_content() for e in pr_dashboard.cssselect('dl.runbot-merge-fields dd')],
+    )) == {
+        'label': f"{config['github']['owner']}:other",
+        'head': c1,
+        'target': 'master',
+    }
 
     with repo:
         repo.post_status(c1, 'success', 'legal/cla')
@@ -3190,7 +3203,7 @@ class TestUnknownPR:
 
         assert prx.comments == [
             (users['reviewer'], 'hansen r+'),
-            (users['user'], "This PR targets the un-managed branch %s:branch, it can not be merged." % repo.name),
+            (users['user'], "This PR targets the un-managed branch %s:branch, it needs to be retargeted before it can be merged." % repo.name),
             (users['user'], "Branch `branch` is not within my remit, imma just ignore it."),
         ]
 
diff --git a/runbot_merge/tests/test_disabled_branch.py b/runbot_merge/tests/test_disabled_branch.py
index eaaca7c4..1d6be201 100644
--- a/runbot_merge/tests/test_disabled_branch.py
+++ b/runbot_merge/tests/test_disabled_branch.py
@@ -1,6 +1,6 @@
-from utils import seen, Commit
+from utils import seen, Commit, pr_page
 
-def test_existing_pr_disabled_branch(env, project, make_repo, setreviewers, config, users):
+def test_existing_pr_disabled_branch(env, project, make_repo, setreviewers, config, users, page):
     """ PRs to disabled branches are ignored, but what if the PR exists *before*
     the branch is disabled?
     """
@@ -13,7 +13,8 @@ def test_existing_pr_disabled_branch(env, project, make_repo, setreviewers, conf
     repo_id = env['runbot_merge.repository'].create({
         'project_id': project.id,
         'name': repo.name,
-        'status_ids': [(0, 0, {'context': 'status'})]
+        'status_ids': [(0, 0, {'context': 'status'})],
+        'group_id': False,
     })
     setreviewers(*project.repo_ids)
 
@@ -25,42 +26,57 @@ def test_existing_pr_disabled_branch(env, project, make_repo, setreviewers, conf
         [c] = repo.make_commits(ot, Commit('wheee', tree={'b': '2'}))
         pr = repo.make_pr(title="title", body='body', target='other', head=c)
         repo.post_status(c, 'success', 'status')
+        pr.post_comment('hansen r+', config['role_reviewer']['token'])
+    env.run_crons()
 
     pr_id = env['runbot_merge.pull_requests'].search([
         ('repository', '=', repo_id.id),
         ('number', '=', pr.number),
     ])
+    branch_id = pr_id.target
+    assert pr_id.staging_id
+    staging_id = branch_id.active_staging_id
+    assert staging_id == pr_id.staging_id
 
     # disable branch "other"
-    project.branch_ids.filtered(lambda b: b.name == 'other').active = False
-
-    # r+ the PR
-    with repo:
-        pr.post_comment('hansen r+', config['role_reviewer']['token'])
+    branch_id.active = False
     env.run_crons()
 
-    # nothing should happen, the PR should be unstaged forever, maybe?
-    assert pr_id.state == 'ready'
+    assert not branch_id.active_staging_id
+    assert staging_id.state == 'cancelled', \
+        "closing the PRs should have canceled the staging"
+
+    p = pr_page(page, pr)
+    target = dict(zip(
+        (e.text for e in p.cssselect('dl.runbot-merge-fields dt')),
+        (p.cssselect('dl.runbot-merge-fields dd'))
+    ))['target']
+    assert target.text_content() == 'other (inactive)'
+    assert target.get('class') == 'text-muted bg-warning'
+
+    # the PR should have been closed implicitly
+    assert pr_id.state == 'closed'
     assert not pr_id.staging_id
 
+    with repo:
+        pr.open()
+        pr.post_comment('hansen r+', config['role_reviewer']['token'])
+    assert pr_id.state == 'ready', "pr should be reopenable"
+    env.run_crons()
+
+    assert pr.comments == [
+        (users['reviewer'], "hansen r+"),
+        seen(env, pr, users),
+        (users['user'], "@%(user)s @%(reviewer)s the target branch 'other' has been disabled, closing this PR." % users),
+        (users['reviewer'], "hansen r+"),
+        (users['user'], "This PR targets the disabled branch %s:other, it needs to be retargeted before it can be merged." % repo.name),
+    ]
+
     with repo:
         [c2] = repo.make_commits(ot, Commit('wheee', tree={'b': '3'}))
         repo.update_ref(pr.ref, c2, force=True)
     assert pr_id.head == c2, "pr should be aware of its update"
 
-    with repo:
-        pr.close()
-    assert pr_id.state == 'closed', "pr should be closeable"
-    with repo:
-        pr.open()
-    assert pr_id.state == 'opened', "pr should be reopenable (state reset due to force push"
-    env.run_crons()
-    assert pr.comments == [
-        (users['reviewer'], "hansen r+"),
-        seen(env, pr, users),
-        (users['user'], "This PR targets the disabled branch %s:other, it can not be merged." % repo.name),
-    ], "reopening a PR to an inactive branch should send feedback, but not closing it"
-
     with repo:
         pr.base = 'other2'
         repo.post_status(c2, 'success', 'status')
@@ -96,7 +112,7 @@ def test_new_pr_no_branch(env, project, make_repo, setreviewers, users):
         ('number', '=', pr.number),
     ]), "the PR should not have been created in the backend"
     assert pr.comments == [
-        (users['user'], "This PR targets the un-managed branch %s:other, it can not be merged." % repo.name),
+        (users['user'], "This PR targets the un-managed branch %s:other, it needs to be retargeted before it can be merged." % repo.name),
     ]
 
 def test_new_pr_disabled_branch(env, project, make_repo, setreviewers, users):
@@ -131,45 +147,6 @@ def test_new_pr_disabled_branch(env, project, make_repo, setreviewers, users):
     assert pr_id, "the PR should have been created in the backend"
     assert pr_id.state == 'opened'
     assert pr.comments == [
-        (users['user'], "This PR targets the disabled branch %s:other, it can not be merged." % repo.name),
+        (users['user'], "This PR targets the disabled branch %s:other, it needs to be retargeted before it can be merged." % repo.name),
         seen(env, pr, users),
     ]
-
-def test_retarget_from_disabled(env, make_repo, project, setreviewers):
-    """ Retargeting a PR from a disabled branch should not duplicate the PR
-    """
-    repo = make_repo('repo')
-    project.write({'branch_ids': [(0, 0, {'name': '1.0'}), (0, 0, {'name': '2.0'})]})
-    repo_id = env['runbot_merge.repository'].create({
-        'project_id': project.id,
-        'name': repo.name,
-        'required_statuses': 'legal/cla,ci/runbot',
-    })
-    setreviewers(repo_id)
-
-    with repo:
-        [c0] = repo.make_commits(None, Commit('0', tree={'a': '0'}), ref='heads/1.0')
-        [c1] = repo.make_commits(c0, Commit('1', tree={'a': '1'}), ref='heads/2.0')
-        repo.make_commits(c1, Commit('2', tree={'a': '2'}), ref='heads/master')
-
-        # create PR on 1.0
-        repo.make_commits(c0, Commit('c', tree={'a': '0', 'b': '0'}), ref='heads/changes')
-        prx = repo.make_pr(head='changes', target='1.0')
-    branch_1 = project.branch_ids.filtered(lambda b: b.name == '1.0')
-    # there should only be a single PR in the system at this point
-    [pr] = env['runbot_merge.pull_requests'].search([])
-    assert pr.target == branch_1
-
-    # branch 1 is EOL, disable it
-    branch_1.active = False
-
-    with repo:
-        # we forgot we had active PRs for it, and we may want to merge them
-        # still, retarget them!
-        prx.base = '2.0'
-
-    # check that we still only have one PR in the system
-    [pr_] = env['runbot_merge.pull_requests'].search([])
-    # and that it's the same as the old one, just edited with a new target
-    assert pr_ == pr
-    assert pr.target == project.branch_ids.filtered(lambda b: b.name == '2.0')
diff --git a/runbot_merge/views/templates.xml b/runbot_merge/views/templates.xml
index 52ca2eed..0e87428d 100644
--- a/runbot_merge/views/templates.xml
+++ b/runbot_merge/views/templates.xml
@@ -404,11 +404,14 @@
                     <t t-else="">open</t>
                 </t>
                 <t t-call="runbot_merge.view_pull_request_info_{{tmpl.strip()}}"/>
+                <t t-set="target_cls" t-value="None if pr.target.active else 'text-muted bg-warning'"/>
                 <dl class="runbot-merge-fields">
                     <dt>label</dt>
                     <dd><span t-field="pr.label"/></dd>
                     <dt>head</dt>
                     <dd><a t-attf-href="{{pr.github_url}}/commits/{{pr.head}}"><span t-field="pr.head"/></a></dd>
+                    <dt t-att-class="target_cls">target</dt>
+                    <dd t-att-class="target_cls"><span t-field="pr.target"/></dd>
                 </dl>
                 <p t-field="pr.message"/>
             </div></div>