diff --git a/typo3/sysext/fluid/Classes/ViewHelpers/Asset/CssViewHelper.php b/typo3/sysext/fluid/Classes/ViewHelpers/Asset/CssViewHelper.php
index 8911f08d849689fcd6cb868395a80ef4461e8d15..532974e2000f821c1b19c15ceb8f8690ab055b68 100644
--- a/typo3/sysext/fluid/Classes/ViewHelpers/Asset/CssViewHelper.php
+++ b/typo3/sysext/fluid/Classes/ViewHelpers/Asset/CssViewHelper.php
@@ -84,7 +84,7 @@ class CssViewHelper extends AbstractTagBasedViewHelper
 
     public function render(): string
     {
-        $identifier = $this->arguments['identifier'];
+        $identifier = (string)$this->arguments['identifier'];
         $attributes = $this->tag->getAttributes();
         $file = $this->tag->getAttribute('href');
         unset($attributes['href']);
diff --git a/typo3/sysext/fluid/Classes/ViewHelpers/Asset/ScriptViewHelper.php b/typo3/sysext/fluid/Classes/ViewHelpers/Asset/ScriptViewHelper.php
index 0dd97ad46de11a00b72dd20fb8dc2e70ec589523..086c7f8d1299069ac69f6436407d2943690a1fa1 100644
--- a/typo3/sysext/fluid/Classes/ViewHelpers/Asset/ScriptViewHelper.php
+++ b/typo3/sysext/fluid/Classes/ViewHelpers/Asset/ScriptViewHelper.php
@@ -80,7 +80,7 @@ class ScriptViewHelper extends AbstractTagBasedViewHelper
 
     public function render(): string
     {
-        $identifier = $this->arguments['identifier'];
+        $identifier = (string)$this->arguments['identifier'];
         $attributes = $this->tag->getAttributes();
         $src = $this->tag->getAttribute('src');
         unset($attributes['src']);