diff --git a/tests/phpstan/phpstan.neon b/tests/phpstan/phpstan.neon
index 7d5d7cb00..5f5cf5a74 100644
--- a/tests/phpstan/phpstan.neon
+++ b/tests/phpstan/phpstan.neon
@@ -92,6 +92,9 @@ parameters:
             path: '*/system/src/Grav/Common/Debugger.php'
 
         # These errors can be ignored (they depend on installed extensions)
+        -
+            message: '#GdImage#'
+            path: '*/system/src/Grav/Framework/Image/Adapter/GdAdapter.php'
         -
             message: '#Instantiated class (Memcache|Memcached|Redis|RedisException) not found#'
             path: '*/system/src/Grav/Common/Cache.php'