diff --git a/phpstan.neon b/phpstan.neon
index 60935294..0d42c566 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -46,10 +46,6 @@ parameters:
 			message: '#string\\|Stringable#'
 			count: 1
 			path: src/Column/Action.php
-		- # In PHP 8+, the Stringable typehint should be used, and this can be removed.
-			message: '#string\\|Stringable#'
-			count: 1
-			path: src/DataGrid.php
 		- # In PHP 8+, the Stringable typehint should be used, and this can be removed.
 			message: '#string\\|Stringable#'
 			count: 3
diff --git a/src/AggregationFunction/FunctionSum.php b/src/AggregationFunction/FunctionSum.php
index 1ad9fb31..7fb74c42 100644
--- a/src/AggregationFunction/FunctionSum.php
+++ b/src/AggregationFunction/FunctionSum.php
@@ -41,7 +41,7 @@ public function processDataSource(Fluent|QueryBuilder|Collection|Selection|IColl
 				? $this->column
 				: current($dataSource->getRootAliases()) . '.' . $this->column;
 
-			$this->result = $dataSource
+			$this->result = (int) $dataSource
 				->select(sprintf('SUM(%s)', $column))
 				->setMaxResults(1)
 				->setFirstResult(0)
diff --git a/src/DataSource/FilterableDataSource.php b/src/DataSource/FilterableDataSource.php
index ccdbd48a..2cb2e8cd 100644
--- a/src/DataSource/FilterableDataSource.php
+++ b/src/DataSource/FilterableDataSource.php
@@ -14,20 +14,6 @@
 abstract class FilterableDataSource
 {
 
-	abstract protected function getDataSource(): mixed;
-
-	abstract protected function applyFilterDate(FilterDate $filter): void;
-
-	abstract protected function applyFilterDateRange(FilterDateRange $filter): void;
-
-	abstract protected function applyFilterRange(FilterRange $filter): void;
-
-	abstract protected function applyFilterText(FilterText $filter): void;
-
-	abstract protected function applyFilterMultiSelect(FilterMultiSelect $filter): void;
-
-	abstract protected function applyFilterSelect(FilterSelect $filter): void;
-
 	/**
 	 * {@inheritDoc}
 	 *
@@ -64,4 +50,18 @@ public function filter(array $filters): void
 		}
 	}
 
+	abstract protected function getDataSource(): mixed;
+
+	abstract protected function applyFilterDate(FilterDate $filter): void;
+
+	abstract protected function applyFilterDateRange(FilterDateRange $filter): void;
+
+	abstract protected function applyFilterRange(FilterRange $filter): void;
+
+	abstract protected function applyFilterText(FilterText $filter): void;
+
+	abstract protected function applyFilterMultiSelect(FilterMultiSelect $filter): void;
+
+	abstract protected function applyFilterSelect(FilterSelect $filter): void;
+
 }
diff --git a/src/Datagrid.php b/src/Datagrid.php
index 5f2e5275..ad0f48ca 100644
--- a/src/Datagrid.php
+++ b/src/Datagrid.php
@@ -82,6 +82,15 @@ class Datagrid extends Control
 		'_grid_hidden_columns_manipulated',
 	];
 
+	public static string $iconPrefix = 'fa fa-';
+
+	public static string $btnSecondaryClass = 'btn-default btn-secondary';
+
+	/**
+	 * Default form method
+	 */
+	public static string $formMethod = 'post';
+
 	/** @var array|callable[] */
 	public array $onRedraw = [];
 
@@ -149,15 +158,6 @@ class Datagrid extends Control
 	 */
 	public array $filter = [];
 
-	public static string $iconPrefix = 'fa fa-';
-
-	public static string $btnSecondaryClass = 'btn-default btn-secondary';
-
-	/**
-	 * Default form method
-	 */
-	public static string $formMethod = 'post';
-
 	/** @var callable|null */
 	protected $sortCallback = null;
 
@@ -2201,7 +2201,7 @@ public function getPerPage(): int|string
 	}
 
 	/**
-	 * @return array|array|int[]|array|string[]
+	 * @return array|array|int[]|array|string[]|\Stringable[]
 	 */
 	public function getItemsPerPageList(): array
 	{
diff --git a/src/Filter/Filter.php b/src/Filter/Filter.php
index 69c3152d..6ba00ab5 100644
--- a/src/Filter/Filter.php
+++ b/src/Filter/Filter.php
@@ -29,12 +29,12 @@ abstract class Filter
 
 	private ?string $placeholder = null;
 
-	abstract public function getCondition(): array;
-
 	public function __construct(protected Datagrid $grid, protected string $key, protected string $name)
 	{
 	}
 
+	abstract public function getCondition(): array;
+
 	/**
 	 * Get filter key
 	 */
diff --git a/tests/Cases/Utils/TestingDDatagridEntity.php b/tests/Cases/Utils/TestingDDatagridEntity.php
index 6033c88d..2144e95e 100644
--- a/tests/Cases/Utils/TestingDDatagridEntity.php
+++ b/tests/Cases/Utils/TestingDDatagridEntity.php
@@ -30,11 +30,6 @@ class TestingDDatagridEntity
 
 	private ?TestingDDatagridEntity $partner = null;
 
-	final public function getId(): int
-	{
-		return $this->id;
-	}
-
 	public function __construct(array $args)
 	{
 		$this->id = $args['id'];
@@ -43,6 +38,11 @@ public function __construct(array $args)
 		$this->gender = $args['gender'] ?? null;
 	}
 
+	final public function getId(): int
+	{
+		return $this->id;
+	}
+
 	public function getName(): string
 	{
 		return $this->name;