diff --git a/library/Graphite/Graphing/MetricsQuery.php b/library/Graphite/Graphing/MetricsQuery.php
index 93d0c90..6ad9550 100644
--- a/library/Graphite/Graphing/MetricsQuery.php
+++ b/library/Graphite/Graphing/MetricsQuery.php
@@ -62,7 +62,7 @@ class MetricsQuery implements Queryable, Filterable, Fetchable
         $this->dataSource = $dataSource;
     }
 
-    public function from($target, array $fields = null)
+    public function from($target, ?array $fields = null)
     {
         if ($fields !== null) {
             throw new InvalidArgumentException('Fields are not applicable to this kind of query');
diff --git a/library/Graphite/Util/TimeRangePickerTools.php b/library/Graphite/Util/TimeRangePickerTools.php
index d1ebc75..1248dfe 100644
--- a/library/Graphite/Util/TimeRangePickerTools.php
+++ b/library/Graphite/Util/TimeRangePickerTools.php
@@ -41,7 +41,7 @@ final class TimeRangePickerTools
      *
      * @return  UrlParams               The copy
      */
-    public static function copyAllRangeParameters(UrlParams $copy = null, UrlParams $origin = null)
+    public static function copyAllRangeParameters(?UrlParams $copy = null, ?UrlParams $origin = null)
     {
         if ($origin === null) {
             $origin = Url::fromRequest()->getParams();
diff --git a/library/Graphite/Web/Controller/TimeRangePickerTrait.php b/library/Graphite/Web/Controller/TimeRangePickerTrait.php
index 7352b1b..3bd7430 100644
--- a/library/Graphite/Web/Controller/TimeRangePickerTrait.php
+++ b/library/Graphite/Web/Controller/TimeRangePickerTrait.php
@@ -23,11 +23,11 @@ trait TimeRangePickerTrait
     /**
      * Process the given request using the forms
      *
-     * @param   Request $request    The request to be processed
+     * @param   ?Request $request    The request to be processed
      *
      * @return  Request             The request supposed to be processed
      */
-    protected function handleTimeRangePickerRequest(Request $request = null)
+    protected function handleTimeRangePickerRequest(?Request $request = null)
     {
         $this->getTimeRangePickerCommonForm()->handleRequest($request);
         return $this->getTimeRangePickerCustomForm()->handleRequest($request);
diff --git a/library/Graphite/Web/Widget/Graphs.php b/library/Graphite/Web/Widget/Graphs.php
index e49a0eb..ce26ad8 100644
--- a/library/Graphite/Web/Widget/Graphs.php
+++ b/library/Graphite/Web/Widget/Graphs.php
@@ -204,11 +204,11 @@ abstract class Graphs extends AbstractWidget
     /**
      * Process the given request using this widget
      *
-     * @param   Request $request    The request to be processed
+     * @param   ?Request $request    The request to be processed
      *
      * @return  $this
      */
-    public function handleRequest(Request $request = null)
+    public function handleRequest(?Request $request = null)
     {
         if ($request === null) {
             $request = Icinga::app()->getRequest();