diff --git a/core/modules/editor/editor.admin.inc b/core/modules/editor/editor.admin.inc
index 83bc2cf..544a553 100644
--- a/core/modules/editor/editor.admin.inc
+++ b/core/modules/editor/editor.admin.inc
@@ -96,6 +96,7 @@ function editor_image_upload_settings_form(Editor $editor) {
     '#field_suffix' => '</div>',
     '#description' => t('Images larger than these dimensions will be scaled down.'),
     '#states' => $show_if_image_uploads_enabled,
+    '#element_validate' => array('editor_image_upload_settings_validate_dimension'),
   );
   $form['max_dimensions']['width'] = array(
     '#title' => t('Width'),
@@ -126,3 +127,15 @@ function editor_image_upload_settings_form(Editor $editor) {
 
   return $form;
 }
+
+function editor_image_upload_settings_validate_dimension($element, &$form_state) {
+  if (!empty($element['width']['#value']) || !empty($element['height']['#value'])) {
+    foreach (array('width', 'height') as $dimension) {
+      if (!$element[$dimension]['#value']) {
+        $form_state->setError($element[$dimension], t('Both a height and width value must be specified in the @name field.', array('@name' => $element['#title'])));
+        return;
+      }
+    }
+ }
+}
+