diff --git a/pip-tools/requirements.in b/pip-tools/requirements.in
index 1826bc0..5c7de6c 100644
--- a/pip-tools/requirements.in
+++ b/pip-tools/requirements.in
@@ -2,6 +2,9 @@ Flask-Migrate
 Flask-SQLAlchemy>3
 flask
 sqlalchemy
+# Josepy 2+ may introduce backward incompatible changes by droping usage of
+# deprecated PyOpenSSL APIs.
+josepy<2
 acme
 boto3
 cfenv
diff --git a/pyproject.toml b/pyproject.toml
index 3a75c6b..9e0c947 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,5 +31,6 @@ ignore_patterns = ["venv/*", ".venv/*"]
 addopts = ["-vv"]
 filterwarnings = [
   'error',
-  'ignore:X509Extension support in pyOpenSSL is deprecated. You should use the APIs in cryptography.:DeprecationWarning'
+  'ignore:X509Extension support in pyOpenSSL is deprecated. You should use the APIs in cryptography.:DeprecationWarning',
+  'ignore:CSR support in pyOpenSSL is deprecated:DeprecationWarning'
 ]