diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f69dadb8..ea801042 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -63,7 +63,7 @@ jobs:
 
         # To keep matrix size down, only test highest and lowest rubies.
         # See "Lowest supported ruby version" in CONTRIBUTING.md
-        ruby: [ '3.2', '3.3' ]
+        ruby: [ '3.1', '3.3' ]
     steps:
       - name: Checkout source
         uses: actions/checkout@v4