diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 520368b..8dabbd0 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -32,6 +32,8 @@ jobs:
           extensions: exif, phar, openssl
           coverage: none
           ini-values: phar.readonly=Off, error_reporting=-1, display_errors=On, zend.assertions=1
+          # Autoload files generated with Composer 2.3 are not compatible with PHP < 7.0.
+          tools: composer:2.2
 
       - name: Install Composer dependencies
         uses: ramsey/composer-install@v2
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b16d6ed..f0f8511 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -55,6 +55,8 @@ jobs:
           extensions: exif, phar, openssl
           coverage: none
           ini-values: phar.readonly=Off, error_reporting=-1, display_errors=On, zend.assertions=1
+          # Autoload files generated with Composer 2.3 are not compatible with PHP < 7.0.
+          tools: composer:2.2
 
       - name: Install Composer dependencies
         uses: ramsey/composer-install@v2