diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index dd3cc77..8274700 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -291,22 +291,10 @@
 	/**
 	 * Begin Transaction
 	 *
-	 * @param	bool	$test_mode
 	 * @return	bool
 	 */
-	public function trans_begin($test_mode = FALSE)
+	protected function _trans_begin()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
-		// Reset the transaction failure flag.
-		// If the $test_mode flag is set to TRUE transactions will be rolled back
-		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE);
-
 		$this->conn_id->autocommit(FALSE);
 		return is_php('5.5')
 			? $this->conn_id->begin_transaction()
@@ -320,14 +308,8 @@
 	 *
 	 * @return	bool
 	 */
-	public function trans_commit()
+	protected function _trans_commit()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		if ($this->conn_id->commit())
 		{
 			$this->conn_id->autocommit(TRUE);
@@ -344,14 +326,8 @@
 	 *
 	 * @return	bool
 	 */
-	public function trans_rollback()
+	protected function _trans_rollback()
 	{
-		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
-		{
-			return TRUE;
-		}
-
 		if ($this->conn_id->rollback())
 		{
 			$this->conn_id->autocommit(TRUE);