diff --git a/src/wp-content/themes/twentyfourteen/functions.php b/src/wp-content/themes/twentyfourteen/functions.php
index 10125d8dba..c81df1ff3d 100644
--- a/src/wp-content/themes/twentyfourteen/functions.php
+++ b/src/wp-content/themes/twentyfourteen/functions.php
@@ -437,6 +437,26 @@ function twentyfourteen_body_classes( $classes ) {
 }
 add_filter( 'body_class', 'twentyfourteen_body_classes' );
 
+/**
+ * Extend the default WordPress post classes.
+ *
+ * Adds a post class to denote:
+ * Non-password protected page with a post thumbnail.
+ *
+ * @since Twenty Fourteen 1.0
+ *
+ * @param array $classes A list of existing post class values.
+ * @return array The filtered post class list.
+ */
+function twentyfourteen_post_classes( $classes ) {
+	if ( ! post_password_required() && ! is_attachment() && has_post_thumbnail() ) {
+		$classes[] = 'has-post-thumbnail';
+	}
+
+	return $classes;
+}
+add_filter( 'post_class', 'twentyfourteen_post_classes' );
+
 /**
  * Create a nicely formatted and more specific title element text for output
  * in head of document, based on current view.