core/modules/image/image.module     |    3 ++-
 core/modules/picture/picture.module |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index b9ed32d..e700150 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -584,6 +584,7 @@ function image_form_editor_image_dialog_alter(&$form, $form_state) {
     $form['dimensions']['#access'] = FALSE;
 
     $image_options = image_style_options(FALSE);
+    $image_options_keys = array_keys($image_options);
     $form['image_style'] = array(
       '#type' => 'item',
       '#field_prefix' => '<div class="container-inline clearfix">',
@@ -592,7 +593,7 @@ function image_form_editor_image_dialog_alter(&$form, $form_state) {
     $form['image_style']['selection'] = array(
       '#title' => t('Image style'),
       '#type' => 'select',
-      '#default_value' => isset($image_element['data-image-style']) ? $image_element['data-image-style'] : array_keys($image_options)[0],
+      '#default_value' => isset($image_element['data-image-style']) ? $image_element['data-image-style'] : $image_options_keys[0],
       '#options' => $image_options,
       '#required' => TRUE,
       '#wrapper_attributes' => array('class' => array('container-inline')),
diff --git a/core/modules/picture/picture.module b/core/modules/picture/picture.module
index e1ef069..33b5a5b 100644
--- a/core/modules/picture/picture.module
+++ b/core/modules/picture/picture.module
@@ -426,10 +426,11 @@ function picture_form_editor_image_dialog_alter(&$form, $form_state) {
         }
       }
     }
+    $picture_options_keys = array_keys($picture_options);
     $form['picture_mapping']['selection'] = array(
       '#title' => t('Image style'),
       '#type' => 'select',
-      '#default_value' => isset($image_element['data-picture-mapping']) ? $image_element['data-picture-mapping'] : array_keys($picture_options)[0],
+      '#default_value' => isset($image_element['data-picture-mapping']) ? $image_element['data-picture-mapping'] : $picture_options_keys[0],
       '#options' => $picture_options,
       '#required' => TRUE,
       '#wrapper_attributes' => array('class' => array('container-inline')),