diff --git a/lib/Doctrine/ORM/Tools/Pagination/LimitSubqueryOutputWalker.php b/lib/Doctrine/ORM/Tools/Pagination/LimitSubqueryOutputWalker.php
index a0ccc982d..3943cb5e6 100644
--- a/lib/Doctrine/ORM/Tools/Pagination/LimitSubqueryOutputWalker.php
+++ b/lib/Doctrine/ORM/Tools/Pagination/LimitSubqueryOutputWalker.php
@@ -179,10 +179,12 @@ class LimitSubqueryOutputWalker extends SqlWalker
         $orderBy         = array();
         if (isset($AST->orderByClause)) {
             foreach ($AST->orderByClause->orderByItems as $item) {
-                $possibleAliases = array_keys($this->rsm->fieldMappings, $item->expression->field);
+                $possibleAliases = (is_object($item->expression))
+                    ? array_keys($this->rsm->fieldMappings, $item->expression->field)
+                    : array_keys($this->rsm->scalarMappings, $item->expression);
 
                 foreach ($possibleAliases as $alias) {
-                    if ($this->rsm->columnOwnerMap[$alias] == $item->expression->identificationVariable) {
+                    if (!is_object($item->expression) || $this->rsm->columnOwnerMap[$alias] == $item->expression->identificationVariable) {
                         $sqlOrderColumns[] = $alias;
                         $orderBy[]         = $alias . ' ' . $item->type;
                         break;
diff --git a/tests/Doctrine/Tests/ORM/Tools/Pagination/LimitSubqueryOutputWalkerTest.php b/tests/Doctrine/Tests/ORM/Tools/Pagination/LimitSubqueryOutputWalkerTest.php
index 362ffc0c8..f19b8520b 100644
--- a/tests/Doctrine/Tests/ORM/Tools/Pagination/LimitSubqueryOutputWalkerTest.php
+++ b/tests/Doctrine/Tests/ORM/Tools/Pagination/LimitSubqueryOutputWalkerTest.php
@@ -36,6 +36,44 @@ class LimitSubqueryOutputWalkerTest extends PaginationTestCase
         $this->entityManager->getConnection()->setDatabasePlatform($odp);
     }
 
+    public function testLimitSubqueryWithScalarSortPg()
+    {
+        $odp = $this->entityManager->getConnection()->getDatabasePlatform();
+        $this->entityManager->getConnection()->setDatabasePlatform(new \Doctrine\DBAL\Platforms\PostgreSqlPlatform);
+
+        $query = $this->entityManager->createQuery(
+            'SELECT u, g, COUNT(g.id) AS g_quantity FROM Doctrine\Tests\ORM\Tools\Pagination\User u JOIN u.groups g ORDER BY g_quantity'
+        );
+        $limitQuery = clone $query;
+        $limitQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, 'Doctrine\ORM\Tools\Pagination\LimitSubqueryOutputWalker');
+
+        $this->assertEquals(
+            "SELECT DISTINCT id1, sclr0 FROM (SELECT COUNT(g0_.id) AS sclr0, u1_.id AS id1, g0_.id AS id2 FROM User u1_ INNER JOIN user_group u2_ ON u1_.id = u2_.user_id INNER JOIN groups g0_ ON g0_.id = u2_.group_id ORDER BY sclr0 ASC) dctrn_result ORDER BY sclr0 ASC",
+            $limitQuery->getSql()
+        );
+
+        $this->entityManager->getConnection()->setDatabasePlatform($odp);
+    }
+
+    public function testLimitSubqueryWithMixedSortPg()
+    {
+        $odp = $this->entityManager->getConnection()->getDatabasePlatform();
+        $this->entityManager->getConnection()->setDatabasePlatform(new \Doctrine\DBAL\Platforms\PostgreSqlPlatform);
+
+        $query = $this->entityManager->createQuery(
+            'SELECT u, g, COUNT(g.id) AS g_quantity FROM Doctrine\Tests\ORM\Tools\Pagination\User u JOIN u.groups g ORDER BY g_quantity, u.id DESC'
+        );
+        $limitQuery = clone $query;
+        $limitQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, 'Doctrine\ORM\Tools\Pagination\LimitSubqueryOutputWalker');
+
+        $this->assertEquals(
+            "SELECT DISTINCT id1, sclr0 FROM (SELECT COUNT(g0_.id) AS sclr0, u1_.id AS id1, g0_.id AS id2 FROM User u1_ INNER JOIN user_group u2_ ON u1_.id = u2_.user_id INNER JOIN groups g0_ ON g0_.id = u2_.group_id ORDER BY sclr0 ASC, u1_.id DESC) dctrn_result ORDER BY sclr0 ASC, id1 DESC",
+            $limitQuery->getSql()
+        );
+
+        $this->entityManager->getConnection()->setDatabasePlatform($odp);
+    }
+
     public function testLimitSubqueryPg()
     {
         $odp = $this->entityManager->getConnection()->getDatabasePlatform();