diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2d0f4fdd..f8d932fc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,6 +24,7 @@ on:
       RUBY_VERSION:
         required: false
         type: string
+        default: "3.0.6"
       PUSH:
         required: false
         type: boolean