diff --git a/.ci/prep_azure.py b/.ci/prep_azure.py
index 80dbf485..fd8fb694 100755
--- a/.ci/prep_azure.py
+++ b/.ci/prep_azure.py
@@ -84,6 +84,12 @@ else:
 if need_to_fix_psycopg2:
     venv_steps.append('/tmp/venv/bin/pip3 install psycopg2==2.8.5 psycopg2-binary')
 
+venv_steps.extend([
+    # pbr is a transitive setup_requires of hdrhistogram. If it's not already
+    # installed then setuptools attempts to use easy_install, which fails.
+    '/tmp/venv/bin/pip install pbr==5.6.0',
+])
+
 batches.append(venv_steps)
 
 ci_lib.run_batches(batches)
diff --git a/ansible_mitogen/planner.py b/ansible_mitogen/planner.py
index a17189a3..90d5bb3c 100644
--- a/ansible_mitogen/planner.py
+++ b/ansible_mitogen/planner.py
@@ -322,6 +322,7 @@ class NewStylePlanner(ScriptPlanner):
     ALWAYS_FORK_MODULES = frozenset([
         'dnf',  # issue #280; py-dnf/hawkey need therapy
         'firewalld',  # issue #570: ansible module_utils caches dbus conn
+        'ansible.legacy.dnf',  # issue #776
     ])
 
     def should_fork(self):
diff --git a/tests/requirements.txt b/tests/requirements.txt
index 76e6545d..21ef8166 100644
--- a/tests/requirements.txt
+++ b/tests/requirements.txt
@@ -12,6 +12,7 @@ timeoutcontext==1.2.0
 unittest2==1.1.0
 # Fix InsecurePlatformWarning while creating py26 tox environment
 # https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
-urllib3[secure]; python_version < '2.7.9'
+urllib3[secure]==1.23; python_version < '2.7'
+urllib3[secure]==1.26; python_version > '2.6' and python_version < '2.7.9'
 # Last idna compatible with Python 2.6 was idna 2.7.
 idna==2.7; python_version < '2.7'
diff --git a/tests/testlib.py b/tests/testlib.py
index e16309ee..019b35d7 100644
--- a/tests/testlib.py
+++ b/tests/testlib.py
@@ -423,7 +423,10 @@ class DockerizedSshDaemon(object):
     def _get_container_port(self):
         s = subprocess__check_output(['docker', 'port', self.container_name])
         for line in s.decode().splitlines():
-            dport, proto, baddr, bport = self.PORT_RE.match(line).groups()
+            m = self.PORT_RE.match(line)
+            if not m:
+                continue
+            dport, proto, _, bport = m.groups()
             if dport == '22' and proto == 'tcp':
                 self.port = int(bport)