diff --git a/.github/workflows/test_fast.yml b/.github/workflows/test_fast.yml
index 34d151b7737..6530bb85cd6 100644
--- a/.github/workflows/test_fast.yml
+++ b/.github/workflows/test_fast.yml
@@ -29,7 +29,7 @@ jobs:
           # non-utc timezone test
           - os: 'ubuntu-latest'
             python-version: '3.9'  # not the oldest, not the most recent version
-            time-zone: ['XXX-09:35']
+            time-zone: 'XXX-09:35'
 
     env:
       # Use non-UTC time zone