diff --git a/zerver/lib/user_agent.py b/zerver/lib/user_agent.py
index 5aa5156b6f..2f2496a3d5 100644
--- a/zerver/lib/user_agent.py
+++ b/zerver/lib/user_agent.py
@@ -4,11 +4,13 @@ from typing import Dict
 # Warning: If you change this parsing, please test using
 #   zerver/tests/test_decorators.py
 # And extend zerver/tests/fixtures/user_agents_unique with any new test cases
+pattern = re.compile(
+    """^ (?P<name> [^/ ]* [^0-9/(]* )
+    (/ (?P<version> [^/ ]* ))?
+    ([ /] .*)?
+    $""", re.X)
+
 def parse_user_agent(user_agent: str) -> Dict[str, str]:
-    match = re.match(
-        """^ (?P<name> [^/ ]* [^0-9/(]* )
-             (/ (?P<version> [^/ ]* ))?
-             ([ /] .*)?
-           $""", user_agent, re.X)
+    match = pattern.match(user_agent)
     assert match is not None
     return match.groupdict()