diff --git a/wp-content/themes/twentythirteen/functions.php b/wp-content/themes/twentythirteen/functions.php
index 295d9e23d9..0c13d6afd9 100644
--- a/wp-content/themes/twentythirteen/functions.php
+++ b/wp-content/themes/twentythirteen/functions.php
@@ -512,6 +512,23 @@ function twentythirteen_body_class( $classes ) {
 }
 add_filter( 'body_class', 'twentythirteen_body_class' );
 
+/**
+ * Extends the default WordPress comment class to add 'no-avatars' class
+ * if avatars are disabled in discussion settings.
+ *
+ * @since Twenty Thirteen 1.0
+ *
+ * @param array $classes Existing class values.
+ * @return array Filtered class values.
+ */
+function twentythirteen_comment_class( $classes ) {
+	if ( ! get_option ( 'show_avatars' ) )
+		$classes[] = 'no-avatars';
+
+	return $classes;
+}
+add_filter( 'comment_class', 'twentythirteen_comment_class' );
+
 /**
  * Adjusts content_width value for image post formats, video post formats, and
  * image attachment templates.
diff --git a/wp-content/themes/twentythirteen/style.css b/wp-content/themes/twentythirteen/style.css
index 0a778706e9..e217f5ae48 100644
--- a/wp-content/themes/twentythirteen/style.css
+++ b/wp-content/themes/twentythirteen/style.css
@@ -2244,6 +2244,18 @@ footer.entry-meta {
 	font-style: normal;
 }
 
+.no-avatars .comment-author {
+	float: none;
+	margin: 0 0 5px;
+	max-width: 100%;
+}
+
+.no-avatars .comment-meta,
+.no-avatars .comment-content,
+.no-avatars .reply {
+	width: 100%;
+}
+
 .bypostauthor .fn:before {
 	content: '\f408';
 }