diff --git a/.github/workflows/phpunit-32bits.yml b/.github/workflows/phpunit-32bits.yml
index 17453968be013..1d7defca9a2f7 100644
--- a/.github/workflows/phpunit-32bits.yml
+++ b/.github/workflows/phpunit-32bits.yml
@@ -39,14 +39,14 @@ jobs:
           submodules: true
 
       - name: Set up dependencies
-        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit:latest
+        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit@sha256:f0e6b5496ad768064c1af727f607f8bcd0eca60cf46987515040b834ed6a14aa
         with:
           args: /bin/sh -c "
             git config --global --add safe.directory /github/workspace &&
             composer install --no-interaction"
 
       - name: Set up Nextcloud
-        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit:latest
+        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit@sha256:f0e6b5496ad768064c1af727f607f8bcd0eca60cf46987515040b834ed6a14aa
         with:
           args: /bin/sh -c "
             mkdir data &&
@@ -54,6 +54,6 @@ jobs:
             php -f tests/enable_all.php"
 
       - name: PHPUnit
-        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit:latest
+        uses: docker://ghcr.io/nextcloud/continuous-integration-php8.4-32bit@sha256:f0e6b5496ad768064c1af727f607f8bcd0eca60cf46987515040b834ed6a14aa
         with:
           args: /bin/sh -c "composer run test -- --exclude-group PRIMARY-azure,PRIMARY-s3,PRIMARY-swift,Memcached,Redis,RoutingWeirdness"