diff --git a/composer.json b/composer.json
index 940b515..8b071cc 100644
--- a/composer.json
+++ b/composer.json
@@ -39,7 +39,8 @@
         "allow-plugins": {
             "composer/package-versions-deprecated": true,
             "simplesamlphp/composer-module-installer": true,
-            "dealerdirect/phpcodesniffer-composer-installer": true
+            "dealerdirect/phpcodesniffer-composer-installer": true,
+            "phpstan/extension-installer": true
         }
     }
 }