diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index d48cb90f..f0d127e5 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         ruby:
-        - '1.9'
+        - '1.9.3'
         - '2.7'
         - '3.0'
         - '3.1'