diff --git a/google-analytics-admin/composer.json b/google-analytics-admin/composer.json
index 14f0f4c..75bd049 100644
--- a/google-analytics-admin/composer.json
+++ b/google-analytics-admin/composer.json
@@ -5,7 +5,7 @@
     "require-dev": {
         "google/cloud-tools": "dev-main",
         "squizlabs/php_codesniffer": "^3.5",
-        "phpunit/phpunit": "^9.0",
+        "phpunit/phpunit": "^12.0",
         "friendsofphp/php-cs-fixer": "^3.46"
     }
 }
diff --git a/google-analytics-data/composer.json b/google-analytics-data/composer.json
index 9671c94..7e78b1c 100644
--- a/google-analytics-data/composer.json
+++ b/google-analytics-data/composer.json
@@ -5,7 +5,7 @@
     "require-dev": {
         "google/cloud-tools": "dev-main",
         "squizlabs/php_codesniffer": "^3.5",
-        "phpunit/phpunit": "^9.0",
+        "phpunit/phpunit": "^12.0",
         "friendsofphp/php-cs-fixer": "^3.46"
     }
 }