diff --git a/.ci/ansible_install.py b/.ci/ansible_install.py
index b2da2702..86e57096 100755
--- a/.ci/ansible_install.py
+++ b/.ci/ansible_install.py
@@ -6,7 +6,7 @@ batches = [
     [
         # Must be installed separately, as PyNACL indirect requirement causes
         # newer version to be installed if done in a single pip run.
-        'pip install "pycparser<2.19"',
+        'pip install "pycparser<2.19" "idna<2.7"',
         'pip install '
             '-r tests/requirements.txt '
             '-r tests/ansible/requirements.txt',