Michael Strelan
--- a/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
+++ b/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
   *   IMAGETYPE_* constant (e.g. IMAGETYPE_JPEG, IMAGETYPE_PNG, etc.).
   */
  protected static function supportedTypes() {
-    return [IMAGETYPE_PNG, IMAGETYPE_JPEG, IMAGETYPE_GIF];
+    $types = [IMAGETYPE_PNG, IMAGETYPE_JPEG, IMAGETYPE_GIF];
+    if (\Drupal::state()->get('image_test.avif_enabled', FALSE)) {