diff --git a/src/lib/MVC/Symfony/Matcher/ContentBased/IsPreview.php b/src/lib/MVC/Symfony/Matcher/ContentBased/IsPreview.php
index 18a326c7f6..c9221cc466 100644
--- a/src/lib/MVC/Symfony/Matcher/ContentBased/IsPreview.php
+++ b/src/lib/MVC/Symfony/Matcher/ContentBased/IsPreview.php
@@ -18,7 +18,7 @@
  */
 final class IsPreview implements ViewMatcherInterface
 {
-    private bool $isPreview;
+    private bool $isPreview = true;
 
     /**
      * @throws \Ibexa\Contracts\Core\Repository\Exceptions\InvalidArgumentException