diff --git a/src/Element/VideoEmbedIFrame.php b/src/Element/VideoEmbedIFrame.php
index b6f94ca..b47f34f 100644
--- a/src/Element/VideoEmbedIFrame.php
+++ b/src/Element/VideoEmbedIFrame.php
@@ -29,7 +29,7 @@ class VideoEmbedIFrame extends RenderElement {
       '#query' => [],
       '#attributes' => [],
       '#pre_render' => [
-        [get_class($this), 'preRenderInlineFrameEmbed']
+        [static::class, 'preRenderInlineFrameEmbed']
       ],
     ];
   }
diff --git a/video_embed_field.module b/video_embed_field.module
index 9a3cc17..879f216 100644
--- a/video_embed_field.module
+++ b/video_embed_field.module
@@ -13,8 +13,8 @@ function video_embed_field_theme() {
     'video_embed_iframe' => [
       'variables' => [
         'url' => '',
-        'query' => NULL,
-        'attributes' => NULL,
+        'query' => [],
+        'attributes' => [],
       ],
     ],
   ];