diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 28766ba..74d5224 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,4 +1,4 @@
-name: Continous integration
+name: Continuous integration
 on:
   pull_request:
   push:
@@ -34,10 +34,10 @@ jobs:
     needs: [test, cs]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 21
       - run: >
           npx
           -p "@semantic-release/commit-analyzer"
diff --git a/src/Module.php b/src/Module.php
index a6ce2df..36304fb 100644
--- a/src/Module.php
+++ b/src/Module.php
@@ -45,6 +45,8 @@ final class Module extends \yii\base\Module
         'post_max_size' => '25M'
     ];
 
+    public string $envJsonFile = '/runtime/env.json';
+
     /**
      * @var array<string, string> $fpmConfig Global directives
      * @see http://php.net/manual/en/install.fpm.configuration.php
@@ -105,28 +107,11 @@ private function createEntrypoint(string $entryScript): string
         $result = [];
         $result[] = '#!/bin/sh';
 
-        // Check if runtime directory is writable.
-        $result[] = <<<SH
-su nobody -s /bin/touch /runtime/testfile && rm /runtime/testfile;
-if [ $? -ne 0 ]; then
-  echo Runtime directory is not writable;
-  exit 1
-fi
-SH;
-
-        // Check if runtime is a tmpfs.
-        $message = Console::ansiFormat('/runtime should really be a tmpfs.', [Console::FG_RED]);
-        $result[] = <<<SH
-grep 'tmpfs /runtime' /proc/mounts;
-if [ $? -ne 0 ]; then
-  echo $message;
-fi
-SH;
         $result[] = <<<SH
-su nobody -s /bin/touch /runtime/env.json
-jq -n -s 'env' > /runtime/env.json
+su nobody -s /bin/touch {$this->envJsonFile}
+jq -n -s 'env' > {$this->envJsonFile}
 if [ $? -ne 0 ]; then
-  echo "failed to store env in /runtime/env.json";
+  echo "failed to store env in {$this->envJsonFile}";
   exit 1
 fi
 SH;
@@ -174,8 +159,6 @@ public function createBuildContext(
 
         $context->from($this->baseImage);
         $context->run('apk add --update --no-cache jq');
-        $context->run('mkdir -p /runtime && chown nobody:nobody /runtime');
-        $context->volume('/runtime');
         $context->copyFromLayer("/project", "0", "/build");
 
         $context->add('/entrypoint.sh', $this->createEntrypoint($entryScript));