diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 32ace3f8a..a97f4255b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,8 +35,10 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~/.composer/cache
-          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
-          restore-keys: ${{ runner.os }}-php-
+          key: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-php-${{ matrix.php-version }}-
+            ${{ runner.os }}-php-
 
       - name: Install Dependencies
         run: composer install --no-progress --prefer-dist
@@ -61,7 +63,7 @@ jobs:
           touch ./INSTALL_BLOCK
 
           cd docker/
-          docker compose -f docker-compose-test.yml up -d
+          PHP_VERSION=${{ matrix.php-version }} docker compose -f docker-compose-test.yml up -d --build
 
           echo "Waiting for BOTH databases..."
           opencatsdb_container="$(docker compose -f docker-compose-test.yml ps -q opencatsdb)"
diff --git a/docker/docker-compose-test.yml b/docker/docker-compose-test.yml
index d27f00012..a48874e02 100644
--- a/docker/docker-compose-test.yml
+++ b/docker/docker-compose-test.yml
@@ -13,6 +13,8 @@ services:
       build:
         context: ..
         dockerfile: docker/php/Dockerfile
+        args:
+          PHP_VERSION: ${PHP_VERSION:-7.4}
       working_dir: /var/www/public
       volumes_from:
         - opencatsdata
diff --git a/docker/php/Dockerfile b/docker/php/Dockerfile
index 9b4670333..b1f2446af 100644
--- a/docker/php/Dockerfile
+++ b/docker/php/Dockerfile
@@ -1,4 +1,5 @@
-FROM php:7.4-fpm-alpine
+ARG PHP_VERSION=7.4
+FROM php:${PHP_VERSION}-fpm-alpine
 
 # Runtime/system packages required by OpenCATS and helper tools.
 RUN apk add --no-cache \