diff --git a/lib/session/CacheSessionHandler.php b/lib/session/CacheSessionHandler.php
index 6eea688e4b58304fa455ec5c94496bf0304ab2a0..0418e47f17f8fc6663ae959c0a3cb2c1764573a6 100644
--- a/lib/session/CacheSessionHandler.php
+++ b/lib/session/CacheSessionHandler.php
@@ -62,7 +62,7 @@ class CacheSessionHandler implements
     public function read(string $id): string|false
     {
         $cache_key = self::CACHE_KEY_PREFIX . '/' . $id;
-        return $this->cache->read($cache_key);
+        return $this->cache->read($cache_key) ?: '';
     }
 
     public function write(string $id, string $data): bool