diff --git a/tests/test_ua.yaml b/tests/test_ua.yaml
index 71bdb3b3..3568580a 100644
--- a/tests/test_ua.yaml
+++ b/tests/test_ua.yaml
@@ -6783,6 +6783,12 @@ test_cases:
     minor: '6'
     patch: '0'
 
+  - user_agent_string: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Slack/2.6.0-beta18998559 Chrome/56.0.2924.87 AtomShell/1.6.3 Safari/537.36 Slack_SSB/2.6.0'
+    family: 'Slack Desktop Client'
+    major: '2'
+    minor: '6'
+    patch: '0'
+
   - user_agent_string: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/603.1.30 (KHTML, like Gecko) HipChat/732 (modern)'
     family: 'HipChat Desktop Client'
     major: '732'