diff --git a/subiquity/server/ubuntu_advantage.py b/subiquity/server/ubuntu_advantage.py
index 48abc8fd..0b43c207 100644
--- a/subiquity/server/ubuntu_advantage.py
+++ b/subiquity/server/ubuntu_advantage.py
@@ -328,8 +328,8 @@ class UAInterface:
         info = await self.get_subscription_status(token)
 
         # Sometimes, a time zone offset of 0 is replaced by the letter Z. This
-        # is specified in RFC 3339 but not supported by fromisoformat.
-        # See https://bugs.python.org/issue35829
+        # is specified in RFC 3339 but not supported by fromisoformat before
+        # Python 3.11. See https://bugs.python.org/issue35829
         expiration = dt.fromisoformat(info["expires"].replace("Z", "+00:00"))
         if expiration.timestamp() <= dt.utcnow().timestamp():
             raise ExpiredTokenError(token, expires=info["expires"])