diff --git a/includes/sqlite-database-integration/activate.php b/includes/sqlite-database-integration/activate.php
index d6d76c377..6af9ba198 100644
--- a/includes/sqlite-database-integration/activate.php
+++ b/includes/sqlite-database-integration/activate.php
@@ -39,8 +39,10 @@ function sqlite_activation() {
 
 		// Handle upgrading from the performance-lab plugin.
 		if ( isset( $_GET['upgrade-from-pl'] ) ) {
+			global $wp_filesystem;
+			require_once ABSPATH . '/wp-admin/includes/file.php';
 			// Delete the previous db.php file.
-			unlink( WP_CONTENT_DIR . '/db.php' );
+			$wp_filesystem->delete( WP_CONTENT_DIR . '/db.php' );
 			// Deactivate the performance-lab SQLite module.
 			$pl_option_name = defined( 'PERFLAB_MODULES_SETTING' ) ? PERFLAB_MODULES_SETTING : 'perflab_modules_settings';
 			$pl_option      = get_option( $pl_option_name, array() );
diff --git a/includes/sqlite-database-integration/load.php b/includes/sqlite-database-integration/load.php
index 7844d8297..c082c78f9 100644
--- a/includes/sqlite-database-integration/load.php
+++ b/includes/sqlite-database-integration/load.php
@@ -3,7 +3,7 @@
  * Plugin Name: SQLite Database Integration
  * Description: SQLite database driver drop-in.
  * Author: WordPress Performance Team
- * Version: 2.1.1
+ * Version: 2.1.2
  * Requires PHP: 5.6
  * Textdomain: sqlite-database-integration
  *
diff --git a/includes/sqlite-database-integration/readme.txt b/includes/sqlite-database-integration/readme.txt
index 88ce9a5ae..83f67a866 100644
--- a/includes/sqlite-database-integration/readme.txt
+++ b/includes/sqlite-database-integration/readme.txt
@@ -2,9 +2,9 @@
 
 Contributors:      wordpressdotorg, aristath
 Requires at least: 6.0
-Tested up to:      6.1
+Tested up to:      6.4
 Requires PHP:      5.6
-Stable tag:        2.1.1
+Stable tag:        2.1.2
 License:           GPLv2 or later
 License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 Tags:              performance, database
diff --git a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php
index 1789cb90e..b3db03574 100644
--- a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php
+++ b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php
@@ -16,8 +16,6 @@ class WP_SQLite_DB extends wpdb {
 	/**
 	 * Database Handle
 	 *
-	 * @access protected
-	 *
 	 * @var WP_SQLite_Translator
 	 */
 	protected $dbh;
@@ -315,7 +313,6 @@ public function query( $query ) {
 	 * This overrides wpdb::load_col_info(), which uses a mysql function.
 	 *
 	 * @see    wpdb::load_col_info()
-	 * @access protected
 	 */
 	protected function load_col_info() {
 		if ( $this->col_info ) {
diff --git a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php
index 2b39033ac..59c6ae607 100644
--- a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php
+++ b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php
@@ -446,11 +446,11 @@ public function isnull( $field ) {
 	 *
 	 * As 'IF' is a reserved word for PHP, function name must be changed.
 	 *
-	 * @param unknonw $expression the statement to be evaluated as true or false.
-	 * @param unknown $true statement or value returned if $expression is true.
-	 * @param unknown $false statement or value returned if $expression is false.
+	 * @param mixed $expression the statement to be evaluated as true or false.
+	 * @param mixed $true statement or value returned if $expression is true.
+	 * @param mixed $false statement or value returned if $expression is false.
 	 *
-	 * @return unknown
+	 * @return mixed
 	 */
 	public function _if( $expression, $true, $false ) {
 		return ( true === $expression ) ? $true : $false;
diff --git a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php
index ab01d42bd..4f8d8401e 100644
--- a/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php
+++ b/includes/sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-translator.php
@@ -31,8 +31,6 @@ class WP_SQLite_Translator {
 	/**
 	 * Class variable to reference to the PDO instance.
 	 *
-	 * @access private
-	 *
 	 * @var PDO object
 	 */
 	private $pdo;
@@ -180,8 +178,6 @@ class WP_SQLite_Translator {
 	/**
 	 * Class variable to store the result of the query.
 	 *
-	 * @access private
-	 *
 	 * @var array reference to the PHP object
 	 */
 	private $results = null;
@@ -196,8 +192,6 @@ class WP_SQLite_Translator {
 	/**
 	 * Class variable to store the file name and function to cause error.
 	 *
-	 * @access private
-	 *
 	 * @var array
 	 */
 	private $errors;
@@ -205,8 +199,6 @@ class WP_SQLite_Translator {
 	/**
 	 * Class variable to store the error messages.
 	 *
-	 * @access private
-	 *
 	 * @var array
 	 */
 	private $error_messages = array();
@@ -215,7 +207,6 @@ class WP_SQLite_Translator {
 	 * Class variable to store the affected row id.
 	 *
 	 * @var int integer
-	 * @access private
 	 */
 	private $last_insert_id;
 
@@ -1692,9 +1683,9 @@ private function preprocess_string_literal( $value ) {
 	private function preprocess_like_expr( &$token ) {
 		/*
 		 * This code handles escaped wildcards in LIKE clauses.
-		 * If we are within a LIKE experession, we look for \_ and \%, the
+		 * If we are within a LIKE expression, we look for \_ and \%, the
 		 * escaped LIKE wildcards, the ones where we want a literal, not a
-		 * wildcard match. We change the \ escape for an ASCII \x1a (SUB) character,
+		 * wildcard match. We change the \ escape for an ASCII \x1A (SUB) character,
 		 * so the \ characters won't get munged.
 		 * These \_ and \% escape sequences are in the token name, because
 		 * the lexer has already done stripcslashes on the value.
@@ -2424,6 +2415,10 @@ private function strip_sqlite_system_tables( $tables ) {
 			array_filter(
 				$tables,
 				function ( $table ) {
+					// Bail early if $table is not an object.
+					if ( ! is_object( $table ) ) {
+						return true;
+					}
 					$table_name = property_exists( $table, 'Name' ) ? $table->Name : $table->table_name; // phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
 					return ! array_key_exists( $table_name, $this->sqlite_system_tables );
 				},