diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1621ad6..167e12f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,7 +20,6 @@ jobs:
       fail-fast: true
       matrix:
         python-version: [
-	  '3.9',
 	  '3.10',
 	  '3.11'
 	  # '3.12' does not have assertDictContainsSubset.