diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 696fb85d18c..07abf4152cc 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -6,7 +6,7 @@ on: ["pull_request", "push"]
 jobs:
   static-analysis-phpstan:
     name: "Static Analysis with PHPStan"
-    runs-on: "ubuntu-latest"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -25,7 +25,7 @@ jobs:
           tools: "cs2pr"
 
       - name: "Cache dependencies installed with composer"
-        uses: "actions/cache@v1"
+        uses: "actions/cache@v2"
         with:
           path: "~/.composer/cache"
           key: "php-${{ matrix.php-version }}-composer-locked-${{ hashFiles('composer.lock') }}"
@@ -39,7 +39,7 @@ jobs:
 
   static-analysis-psalm:
     name: "Static Analysis with Psalm"
-    runs-on: "ubuntu-latest"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -71,7 +71,7 @@ jobs:
 
   phpunit-oci8:
     name: "PHPUnit on OCI8"
-    runs-on: "ubuntu-latest"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix:
@@ -115,7 +115,7 @@ jobs:
 
   phpunit-pdo-oci:
     name: "PHPUnit on PDO_OCI"
-    runs-on: "ubuntu-latest"
+    runs-on: "ubuntu-20.04"
 
     strategy:
       matrix: