diff --git a/update-checker/Puc/v5p1/StateStore.php b/update-checker/Puc/v5p1/StateStore.php
index a4b5ecd0..015afd71 100644
--- a/update-checker/Puc/v5p1/StateStore.php
+++ b/update-checker/Puc/v5p1/StateStore.php
@@ -77,7 +77,7 @@ public function getUpdate() {
 		 * @param Update|null $update
 		 * @return $this
 		 */
-		public function setUpdate(Update $update = null) {
+		public function setUpdate(?Update $update = null) {
 			$this->lazyLoad();
 			$this->update = $update;
 			return $this;
diff --git a/update-checker/Puc/v5p1/UpdateChecker.php b/update-checker/Puc/v5p1/UpdateChecker.php
index 300bb89a..245dd538 100644
--- a/update-checker/Puc/v5p1/UpdateChecker.php
+++ b/update-checker/Puc/v5p1/UpdateChecker.php
@@ -459,7 +459,7 @@ protected function filterUpdateResult($update, $httpResult = null) {
 		 *
 		 * @param Metadata|null $update
 		 */
-		protected function fixSupportedWordpressVersion(Metadata $update = null) {
+		protected function fixSupportedWordpressVersion(?Metadata $update = null) {
 			if ( !isset($update->tested) || !preg_match('/^\d++\.\d++$/', $update->tested) ) {
 				return;
 			}
diff --git a/update-checker/vendor/ParsedownModern.php b/update-checker/vendor/ParsedownModern.php
index 5d96071b..2acb90ee 100644
--- a/update-checker/vendor/ParsedownModern.php
+++ b/update-checker/vendor/ParsedownModern.php
@@ -648,7 +648,7 @@ protected function blockRule($Line)
     #
     # Setext
 
-    protected function blockSetextHeader($Line, array $Block = null)
+    protected function blockSetextHeader($Line, ?array $Block = null)
     {
         if ( ! isset($Block) or isset($Block['type']) or isset($Block['interrupted']))
         {
@@ -786,7 +786,7 @@ protected function blockReference($Line)
     #
     # Table
 
-    protected function blockTable($Line, array $Block = null)
+    protected function blockTable($Line, ?array $Block = null)
     {
         if ( ! isset($Block) or isset($Block['type']) or isset($Block['interrupted']))
         {
@@ -1535,4 +1535,4 @@ static function instance($name = 'default')
                    'wbr', 'span',
                           'time',
     );
-}
\ No newline at end of file
+}