diff --git a/typo3/sysext/core/Classes/Http/Uri.php b/typo3/sysext/core/Classes/Http/Uri.php
index 7d1b2740ac27..0bc59af819ea 100644
--- a/typo3/sysext/core/Classes/Http/Uri.php
+++ b/typo3/sysext/core/Classes/Http/Uri.php
@@ -434,14 +434,16 @@ public function withHost($host)
      */
     public function withPort($port)
     {
-        if (\TYPO3\CMS\Core\Utility\MathUtility::canBeInterpretedAsInteger($port) === false) {
-            $argumentType = is_object($port) ? get_class($port) : gettype($port);
-            throw new \InvalidArgumentException('Invalid port "' . $argumentType . '" specified, must be an integer.', 1436717324);
-        }
+        if ($port !== null) {
+            if (\TYPO3\CMS\Core\Utility\MathUtility::canBeInterpretedAsInteger($port) === false) {
+                $argumentType = is_object($port) ? get_class($port) : gettype($port);
+                throw new \InvalidArgumentException('Invalid port "' . $argumentType . '" specified, must be an integer.', 1436717324);
+            }
 
-        $port = (int)$port;
-        if ($port < 1 || $port > 65535) {
-            throw new \InvalidArgumentException('Invalid port "' . $port . '" specified, must be a valid TCP/UDP port.', 1436717326);
+            $port = (int)$port;
+            if ($port < 1 || $port > 65535) {
+                throw new \InvalidArgumentException('Invalid port "' . $port . '" specified, must be a valid TCP/UDP port.', 1436717326);
+            }
         }
 
         $clonedObject = clone $this;
diff --git a/typo3/sysext/core/Tests/Unit/Http/UriTest.php b/typo3/sysext/core/Tests/Unit/Http/UriTest.php
index 85dd41bc0c7f..fb26993c7853 100644
--- a/typo3/sysext/core/Tests/Unit/Http/UriTest.php
+++ b/typo3/sysext/core/Tests/Unit/Http/UriTest.php
@@ -97,6 +97,18 @@ public function withHostReturnsNewInstanceWithProvidedHost()
         $this->assertEquals('https://user:pass@framework.zend.com:3001/foo?bar=baz#quz', (string) $new);
     }
 
+    /**
+     * @test
+     */
+    public function withPortAndNullValueReturnsInstanceWithProvidedPort()
+    {
+        $uri = new Uri('https://user:pass@local.example.com:3001/foo?bar=baz#quz');
+        $new = $uri->withPort(null);
+        $this->assertEquals(
+            'https://user:pass@local.example.com/foo?bar=baz#quz',
+            (string) $new
+        );
+    }
     /**
      * @return array
      */
@@ -130,7 +142,6 @@ public function withPortReturnsNewInstanceWithProvidedPort($port)
     public function invalidPortsDataProviderType()
     {
         return [
-            'null'      => [null],
             'false'     => [false],
             'string'    => ['string'],
             'array'     => [[3000]],