diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index dab7ed2..3971dfe 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -44,6 +44,8 @@ jobs:
           - 3.3.4
           - 3.3.5
           - 3.3.6
+          - 3.4.0
+          - 3.4.1
     steps:
       - name: checkout
         uses: actions/checkout@v4
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..47b322c
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.4.1
diff --git a/.tool-versions b/.tool-versions
deleted file mode 100644
index f2a971a..0000000
--- a/.tool-versions
+++ /dev/null
@@ -1 +0,0 @@
-ruby 3.2.2