diff --git a/lib/Doctrine/ORM/Query/AST/Functions/AvgFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/AvgFunction.php
index d217eb4b7..6cb8d92b6 100644
--- a/lib/Doctrine/ORM/Query/AST/Functions/AvgFunction.php
+++ b/lib/Doctrine/ORM/Query/AST/Functions/AvgFunction.php
@@ -29,7 +29,7 @@ use Doctrine\ORM\Query\AST\AggregateExpression;
  * @since   2.6
  * @author  Mathew Davies <thepixeldeveloper@icloud.com>
  */
-class AvgFunction extends FunctionNode
+final class AvgFunction extends FunctionNode
 {
     /**
      * @var AggregateExpression
diff --git a/lib/Doctrine/ORM/Query/AST/Functions/CountFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/CountFunction.php
index 34a9a723c..f232cf43f 100644
--- a/lib/Doctrine/ORM/Query/AST/Functions/CountFunction.php
+++ b/lib/Doctrine/ORM/Query/AST/Functions/CountFunction.php
@@ -29,7 +29,7 @@ use Doctrine\ORM\Query\AST\AggregateExpression;
  * @since   2.6
  * @author  Mathew Davies <thepixeldeveloper@icloud.com>
  */
-class CountFunction extends FunctionNode
+final class CountFunction extends FunctionNode
 {
     /**
      * @var AggregateExpression
diff --git a/lib/Doctrine/ORM/Query/AST/Functions/MaxFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/MaxFunction.php
index d430cc428..eba9b8639 100644
--- a/lib/Doctrine/ORM/Query/AST/Functions/MaxFunction.php
+++ b/lib/Doctrine/ORM/Query/AST/Functions/MaxFunction.php
@@ -29,7 +29,7 @@ use Doctrine\ORM\Query\AST\AggregateExpression;
  * @since   2.6
  * @author  Mathew Davies <thepixeldeveloper@icloud.com>
  */
-class MaxFunction extends FunctionNode
+final class MaxFunction extends FunctionNode
 {
     /**
      * @var AggregateExpression
diff --git a/lib/Doctrine/ORM/Query/AST/Functions/MinFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/MinFunction.php
index 345f99a94..e1c086913 100644
--- a/lib/Doctrine/ORM/Query/AST/Functions/MinFunction.php
+++ b/lib/Doctrine/ORM/Query/AST/Functions/MinFunction.php
@@ -29,7 +29,7 @@ use Doctrine\ORM\Query\AST\AggregateExpression;
  * @since   2.6
  * @author  Mathew Davies <thepixeldeveloper@icloud.com>
  */
-class MinFunction extends FunctionNode
+final class MinFunction extends FunctionNode
 {
     /**
      * @var AggregateExpression
diff --git a/lib/Doctrine/ORM/Query/AST/Functions/SumFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/SumFunction.php
index d77e284c0..c9fcf7b04 100644
--- a/lib/Doctrine/ORM/Query/AST/Functions/SumFunction.php
+++ b/lib/Doctrine/ORM/Query/AST/Functions/SumFunction.php
@@ -29,7 +29,7 @@ use Doctrine\ORM\Query\AST\AggregateExpression;
  * @since   2.6
  * @author  Mathew Davies <thepixeldeveloper@icloud.com>
  */
-class SumFunction extends FunctionNode
+final class SumFunction extends FunctionNode
 {
     /**
      * @var AggregateExpression