diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a76b09c..e3aadcb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        ruby: [2.6, 2.7, '3.0', 3.1]
+        ruby: [2.7]
     steps:
       # - run: ssh -V
       # - run: |
diff --git a/.ruby-version b/.ruby-version
index 0aec50e..6a81b4c 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.1.4
+2.7.8
diff --git a/Gemfile b/Gemfile
index 44aa113..778f631 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,6 +4,8 @@ source "https://rubygems.org"
 
 git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
+ruby File.read(".ruby-version")
+
 gem "sequel"
 gem "pg"
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 143bbd5..e78cc6b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -14,7 +14,7 @@ DEPENDENCIES
   sequel
 
 RUBY VERSION
-   ruby 3.1.4p223
+   ruby 2.7.8p225
 
 BUNDLED WITH
-   2.5.1
+   2.4.10