diff --git a/src/AggregationFunction/FunctionSum.php b/src/AggregationFunction/FunctionSum.php
index 348f70b2c..f708ec7ef 100644
--- a/src/AggregationFunction/FunctionSum.php
+++ b/src/AggregationFunction/FunctionSum.php
@@ -9,6 +9,9 @@
 use Doctrine\ORM\QueryBuilder;
 use Nette\Database\Table\Selection;
 use Nette\Utils\Strings;
+use Nextras\Orm\Collection\DbalCollection;
+use Symfony\Component\ErrorHandler\Debug;
+use Tracy\Debugger;
 use Ublaboo\DataGrid\Utils\PropertyAccessHelper;
 
 class FunctionSum implements ISingleColumnAggregationFunction
@@ -51,7 +54,7 @@ public function getFilterDataType(): string
 
 
 	/**
-	 * @param Fluent|QueryBuilder|Collection|Selection $dataSource
+	 * @param Fluent|QueryBuilder|Collection|Selection|DbalCollection $dataSource
 	 */
 	public function processDataSource($dataSource): void
 	{
@@ -82,6 +85,11 @@ public function processDataSource($dataSource): void
 				return true;
 			});
 		}
+
+		if ( $dataSource instanceof DbalCollection) {
+			foreach( $dataSource->fetchAll() as $item )
+				$this->result += $item->getValue( $this->column );
+		}
 	}
 
 
diff --git a/src/DataSource/NextrasDataSource.php b/src/DataSource/NextrasDataSource.php
index d497fd9fd..a68214a05 100755
--- a/src/DataSource/NextrasDataSource.php
+++ b/src/DataSource/NextrasDataSource.php
@@ -7,6 +7,8 @@
 use Nette\Utils\Strings;
 use Nextras\Orm\Collection\Expression\LikeExpression;
 use Nextras\Orm\Collection\ICollection;
+use Ublaboo\DataGrid\AggregationFunction\IAggregatable;
+use Ublaboo\DataGrid\AggregationFunction\IAggregationFunction;
 use Ublaboo\DataGrid\Exception\DataGridDateTimeHelperException;
 use Ublaboo\DataGrid\Filter\FilterDate;
 use Ublaboo\DataGrid\Filter\FilterDateRange;
@@ -19,7 +21,7 @@
 use Ublaboo\DataGrid\Utils\Sorting;
 use UnexpectedValueException;
 
-class NextrasDataSource extends FilterableDataSource implements IDataSource
+class NextrasDataSource extends FilterableDataSource implements IDataSource, IAggregatable
 {
 
 	/**
@@ -341,4 +343,13 @@ private function prepareColumn(string $column): string
 
 		return $column;
 	}
+
+	/**
+	 * @param  IAggregationFunction $function
+	 * @return void
+	 */
+     public function processAggregation(IAggregationFunction $function): void
+     {
+		 $function->processDataSource(clone $this->dataSource);
+     }
 }