diff --git a/.github/workflows/deploy-push.yml b/.github/workflows/deploy-push.yml
index 864c296e..a222fe85 100644
--- a/.github/workflows/deploy-push.yml
+++ b/.github/workflows/deploy-push.yml
@@ -29,15 +29,24 @@ jobs:
         uses: shivammathur/setup-php@f3e473d116dcccaddc5834248c87452386958240 # v2.37.2
         with:
           php-version: 8.5
+          # The slides importer's phpoffice packages need zip and gd
+          extensions: zip, gd
+
+      - name: Get Composer cache directory
+        id: composer-cache
+        run: echo "dir=$(composer config cache-files-dir)" >> "$GITHUB_OUTPUT"
 
       - name: Cache Composer dependencies
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
-          path: /tmp/composer-cache
+          path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-${{ hashFiles('**/composer.lock') }}
 
+      # Composer runs on the runner, not in a container, so the plugin installs
+      # in install-ssp get the PHP extensions above, npm and a git checkout the
+      # runner owns
       - name: Install dependencies
-        uses: php-actions/composer@8a65f0d3c6a1d17ca4800491a40b5756a4c164f3 # v6.1.2
+        run: composer install --no-interaction --no-progress --prefer-dist
 
       - name: Install phpcs
         run: vendor/bin/phpcs -i
diff --git a/composer.json b/composer.json
index d1713d56..51df4ad2 100644
--- a/composer.json
+++ b/composer.json
@@ -175,8 +175,8 @@
     "post-update-cmd": [
       "@update-ssp"
     ],
-    "install-ssp": "cd web/app/plugins/cbf-multisite;composer install;cd ../cbf-slides-importer;composer install;cd ../cbf-semantic-glossary;composer install;cd ../cbf-semantic-glossary-learndash;composer install;cd ../../../..",
-    "update-ssp": "cd web/app/plugins/cbf-multisite;composer update;cd ../cbf-slides-importer;composer update;cd ../cbf-semantic-glossary;composer update;cd ../cbf-semantic-glossary-learndash;composer update;cd ../../../..",
+    "install-ssp": "cd web/app/plugins/cbf-multisite && composer install && cd ../cbf-slides-importer && composer install && cd ../cbf-semantic-glossary && composer install && cd ../cbf-semantic-glossary-learndash && composer install && cd ../../../..",
+    "update-ssp": "cd web/app/plugins/cbf-multisite && composer update && cd ../cbf-slides-importer && composer update && cd ../cbf-semantic-glossary && composer update && cd ../cbf-semantic-glossary-learndash && composer update && cd ../../../..",
     "lint": "phpcs --standard=phpcs.xml",
     "lint:all": "@lint ./web/app/plugins/cbf-multisite ./web/app/plugins/cbf-slides-importer ./web/app/plugins/cbf-semantic-glossary ./web/app/plugins/cbf-semantic-glossary-learndash ./web/app/themes/cbf-academy ./web/app/themes/cbf-jobs",
     "fix": "phpcbf --standard=phpcs.xml",