diff --git a/src/wp-admin/includes/upgrade.php b/src/wp-admin/includes/upgrade.php
index b1c4bc28fa..9fd944a097 100644
--- a/src/wp-admin/includes/upgrade.php
+++ b/src/wp-admin/includes/upgrade.php
@@ -527,6 +527,9 @@ function upgrade_all() {
 	if ( $wp_current_db_version < 31351 )
 		upgrade_420();
 
+	if ( $wp_current_db_version < 32308 )
+		upgrade_421();
+
 	maybe_disable_link_manager();
 
 	maybe_disable_automattic_widgets();
@@ -1435,6 +1438,33 @@ function upgrade_420() {
 	}
 }
 
+/**
+ * Execute changes made in WordPress 4.2.1.
+ *
+ * @since 4.2.1
+ */
+function upgrade_421() {
+	global $wp_current_db_version, $wpdb;
+
+	if ( $wp_current_db_version < 32308 ) {
+		$content_length = $wpdb->get_col_length( $wpdb->comments, 'comment_content' );
+		if ( ! $content_length ) {
+			$content_length = 65535;
+		}
+
+		$comments = $wpdb->get_results(
+			"SELECT comment_ID FROM $wpdb->comments
+			WHERE comment_date_gmt > '2015-04-26'
+			AND CHAR_LENGTH( comment_content ) >= $content_length
+			AND ( comment_content LIKE '%<%' OR comment_content LIKE '%>%' )"
+		);
+
+		foreach ( $comments as $comment ) {
+			wp_delete_comment( $comments->comment_ID );
+		}
+	}
+}
+
 /**
  * Executes network-level upgrade routines.
  *
diff --git a/src/wp-includes/version.php b/src/wp-includes/version.php
index 50bc84abb9..ff960d7b73 100644
--- a/src/wp-includes/version.php
+++ b/src/wp-includes/version.php
@@ -11,7 +11,7 @@ $wp_version = '4.3-alpha-32280-src';
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 31532;
+$wp_db_version = 32308;
 
 /**
  * Holds the TinyMCE version