diff --git a/system/database/drivers/mysql/mysql_utility.php b/system/database/drivers/mysql/mysql_utility.php
index f118033..94ef95a 100644
--- a/system/database/drivers/mysql/mysql_utility.php
+++ b/system/database/drivers/mysql/mysql_utility.php
@@ -80,7 +80,7 @@
 		// Do we need to include a statement to disable foreign key checks?
 		if ($foreign_key_checks === FALSE)
 		{
-			$output .= "SET foreign_key_checks = 0;".$newline;
+			$output .= 'SET foreign_key_checks = 0;'.$newline;
 		}
 
 		foreach ( (array) $tables as $table)
@@ -191,7 +191,7 @@
 		// Do we need to include a statement to re-enable foreign key checks?
 		if ($foreign_key_checks === FALSE)
 		{
-			$output .= "SET foreign_key_checks = 1;".$newline;
+			$output .= 'SET foreign_key_checks = 1;'.$newline;
 		}
 
 		return $output;
diff --git a/system/database/drivers/mysqli/mysqli_utility.php b/system/database/drivers/mysqli/mysqli_utility.php
index 2edf38c..f6688bc 100644
--- a/system/database/drivers/mysqli/mysqli_utility.php
+++ b/system/database/drivers/mysqli/mysqli_utility.php
@@ -80,7 +80,7 @@
 		// Do we need to include a statement to disable foreign key checks?
 		if ($foreign_key_checks === FALSE)
 		{
-			$output .= "SET foreign_key_checks = 0;".$newline;
+			$output .= 'SET foreign_key_checks = 0;'.$newline;
 		}
 
 		foreach ( (array) $tables as $table)
@@ -191,7 +191,7 @@
 		// Do we need to include a statement to re-enable foreign key checks?
 		if ($foreign_key_checks === FALSE)
 		{
-			$output .= "SET foreign_key_checks = 1;".$newline;
+			$output .= 'SET foreign_key_checks = 1;'.$newline;
 		}
 
 		return $output;