diff --git a/Neos.Flow/Classes/Aop/Builder/ProxyClassBuilder.php b/Neos.Flow/Classes/Aop/Builder/ProxyClassBuilder.php
index 3157a132eb..b1052792f7 100644
--- a/Neos.Flow/Classes/Aop/Builder/ProxyClassBuilder.php
+++ b/Neos.Flow/Classes/Aop/Builder/ProxyClassBuilder.php
@@ -409,7 +409,7 @@ public function buildProxyClass(string $targetClassName, array $aspectContainers
             $proxyClass->addProperty($propertyName, var_export($propertyIntroduction->getInitialValue(), true), $propertyIntroduction->getPropertyVisibility(), $propertyIntroduction->getPropertyDocComment());
         }
 
-        $proxyClass->getMethod('Flow_Aop_Proxy_buildMethodsAndAdvicesArray')->addPreParentCallCode("        if (method_exists(get_parent_class(), 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray') && is_callable([parent::class, 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray'])) parent::Flow_Aop_Proxy_buildMethodsAndAdvicesArray();\n");
+        $proxyClass->getMethod('Flow_Aop_Proxy_buildMethodsAndAdvicesArray')->addPreParentCallCode("        if (method_exists(get_parent_class(\$this), 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray') && is_callable([parent::class, 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray'])) parent::Flow_Aop_Proxy_buildMethodsAndAdvicesArray();\n");
         $proxyClass->getMethod('Flow_Aop_Proxy_buildMethodsAndAdvicesArray')->addPreParentCallCode($this->buildMethodsAndAdvicesArrayCode($interceptedMethods));
         $proxyClass->getMethod('Flow_Aop_Proxy_buildMethodsAndAdvicesArray')->setVisibility(ProxyMethodGenerator::VISIBILITY_PROTECTED);
 
@@ -420,7 +420,7 @@ public function buildProxyClass(string $targetClassName, array $aspectContainers
 
         if (!$this->reflectionService->hasMethod($targetClassName, '__wakeup')) {
             $proxyClass->getMethod('__wakeup')->addPostParentCallCode(<<<PHP
-            if (method_exists(get_parent_class(), '__wakeup') && is_callable('parent::__wakeup')) parent::__wakeup();
+            if (method_exists(get_parent_class(\$this), '__wakeup') && is_callable([parent::class, '__wakeup'])) parent::__wakeup();
             PHP);
         }
         $proxyClass->addTraits(['\\' . AdvicesTrait::class]);
@@ -495,7 +495,7 @@ protected function addBuildMethodsAndAdvicesCodeToClass(string $className, Class
             return $treatedSubClasses;
         }
 
-        $callBuildMethodsAndAdvicesArrayCode = "        if (method_exists(get_parent_class(), 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray') && is_callable([parent::class, 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray'])) parent::Flow_Aop_Proxy_buildMethodsAndAdvicesArray();\n";
+        $callBuildMethodsAndAdvicesArrayCode = "        if (method_exists(get_parent_class(\$this), 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray') && is_callable([parent::class, 'Flow_Aop_Proxy_buildMethodsAndAdvicesArray'])) parent::Flow_Aop_Proxy_buildMethodsAndAdvicesArray();\n";
         $proxyClass->getConstructor()->addPreParentCallCode($callBuildMethodsAndAdvicesArrayCode);
         $proxyClass->getMethod('__wakeup')->addPreParentCallCode($callBuildMethodsAndAdvicesArrayCode);
 
diff --git a/Neos.Flow/Classes/Mvc/Routing/UriBuilder.php b/Neos.Flow/Classes/Mvc/Routing/UriBuilder.php
index 5ed89be8fe..8cce500867 100644
--- a/Neos.Flow/Classes/Mvc/Routing/UriBuilder.php
+++ b/Neos.Flow/Classes/Mvc/Routing/UriBuilder.php
@@ -159,18 +159,18 @@ public function getSection()
     /**
      * Specifies the format of the target (e.g. "html" or "xml")
      *
-     * @param string $format (e.g. "html" or "xml"), will be transformed to lowercase!
+     * @param string|null $format (e.g. "html" or "xml"), will be transformed to lowercase!
      * @return UriBuilder the current UriBuilder to allow method chaining
      * @api
      */
     public function setFormat($format)
     {
-        $this->format = strtolower($format);
+        $this->format = $format !== null ? strtolower($format) : null;
         return $this;
     }
 
     /**
-     * @return string
+     * @return string|null
      * @api
      */
     public function getFormat()