diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 0cf23015..f4f4d2cf 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   deploy:
     name: Capistrano Deploy to Server
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
       - name: Install SSH key to Server
diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 15b37808..d49fab9f 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -12,7 +12,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     services:
       db:
         image: postgres:11
@@ -44,7 +44,7 @@ jobs:
           bundle exec rake test
   rubocop:
     name: rubocop
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout code
         uses: actions/checkout@v2