diff --git a/lib/Doctrine/ORM/Query/Expr/Func.php b/lib/Doctrine/ORM/Query/Expr/Func.php
index b4ed07cd3b2..644458cddd8 100644
--- a/lib/Doctrine/ORM/Query/Expr/Func.php
+++ b/lib/Doctrine/ORM/Query/Expr/Func.php
@@ -19,6 +19,8 @@
 
 namespace Doctrine\ORM\Query\Expr;
 
+use function count;
+
 /**
  * Expression class for generating DQL functions.
  *
@@ -73,6 +75,10 @@ public function getArguments()
      */
     public function __toString()
     {
+        if (count($this->arguments) === 0) {
+            return $this->name . '(NULL)';
+        }
+
         return $this->name . '(' . implode(', ', $this->arguments) . ')';
     }
 }
diff --git a/tests/Doctrine/Tests/ORM/Query/ExprTest.php b/tests/Doctrine/Tests/ORM/Query/ExprTest.php
index 37a4b70a657..69a999e302b 100644
--- a/tests/Doctrine/Tests/ORM/Query/ExprTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/ExprTest.php
@@ -282,6 +282,11 @@ public function testInLiteralExpr()
         $this->assertEquals("u.type IN('foo', 'bar')", (string) $this->_expr->in('u.type', ['foo', 'bar']));
     }
 
+    public function testInExprForEmptyArray()
+    {
+        self::assertEquals('u.id IN(NULL)', (string) $this->_expr->in('u.id', []));
+    }
+
     public function testNotInExpr()
     {
         $this->assertEquals('u.id NOT IN(1, 2, 3)', (string) $this->_expr->notIn('u.id', [1, 2, 3]));
@@ -292,6 +297,11 @@ public function testNotInLiteralExpr()
         $this->assertEquals("u.type NOT IN('foo', 'bar')", (string) $this->_expr->notIn('u.type', ['foo', 'bar']));
     }
 
+    public function testNotInExprForEmptyArray()
+    {
+        self::assertEquals('u.id NOT IN(NULL)', (string) $this->_expr->notIn('u.id', []));
+    }
+
     public function testAndxOrxExpr()
     {
         $andExpr = $this->_expr->andX();