diff --git a/Test/Export/AbstractAggregatorTest.php b/Test/Export/AbstractAggregatorTest.php
index c03fecfc6..a1f0cf60a 100644
--- a/Test/Export/AbstractAggregatorTest.php
+++ b/Test/Export/AbstractAggregatorTest.php
@@ -210,19 +210,28 @@ abstract class AbstractAggregatorTest extends KernelTestCase
     public function testAlterQuery(QueryBuilder $query, $data)
     {
         // retains informations about query
-        $nbOfFrom   = count($query->getDQLPart('from'));
-        $nbOfWhere  = count($query->getDQLPart('where'));
-        $nbOfSelect = count($query->getDQLPart('select'));
+        $nbOfFrom   = $query->getDQLPart('from') !== null ? 
+            count($query->getDQLPart('from')) : 0;
+        $nbOfWhere  = $query->getDQLPart('where') !== null ? 
+            count($query->getDQLPart('where')) : 0;
+        $nbOfSelect = $query->getDQLPart('select') !== null ?
+            count($query->getDQLPart('select')) : 0;
         
         $this->getAggregator()->alterQuery($query, $data);
         
-        $this->assertGreaterThanOrEqual($nbOfFrom, count($query->getDQLPart('from')),
+        $this->assertGreaterThanOrEqual(
+            $nbOfFrom, 
+            $query->getDQLPart('from') !== null ? count($query->getDQLPart('from')) : 0,
             "Test that there are equal or more 'from' clause after that the filter has 
                 altered the query");
-        $this->assertGreaterThanOrEqual($nbOfWhere, count($query->getDQLPart('where')),
+        $this->assertGreaterThanOrEqual(
+            $nbOfWhere, 
+            $query->getDQLPart('where') !== null ? count($query->getDQLPart('where')) : 0,
             "Test that there are equal or more 'where' clause after that the filter has"
             . "altered the query");
-        $this->assertGreaterThanOrEqual($nbOfSelect, count($query->getDQLPart('select')),
+        $this->assertGreaterThanOrEqual(
+            $nbOfSelect, 
+            $query->getDQLPart('select') !== null ? count($query->getDQLPart('select')) : 0,
             "Test that the filter has no altered the 'select' part of the query");
         
     }