diff --git a/src/Boot/src/Memory.php b/src/Boot/src/Memory.php
index d2f42ece6..5a4f179fb 100644
--- a/src/Boot/src/Memory.php
+++ b/src/Boot/src/Memory.php
@@ -24,9 +24,9 @@ public function __construct(
     }
 
     /**
-     * @param string $filename Cache filename.
+     * @param non-empty-string|null $filename Cache filename.
      */
-    public function loadData(string $section, string &$filename = null): mixed
+    public function loadData(string $section, ?string &$filename = null): mixed
     {
         $filename = $this->getFilename($section);
 
@@ -34,17 +34,27 @@ public function loadData(string $section, string &$filename = null): mixed
             return null;
         }
 
+        $fp = false;
+        $lock = false;
+
         try {
             $fp = \fopen($filename, 'r');
-            if (!\flock($fp, \LOCK_SH | \LOCK_NB)) {
+            if ($fp === false) {
+                return null;
+            }
+
+            $lock = \flock($fp, \LOCK_SH | \LOCK_NB);
+
+            if ($lock === false) {
                 return null;
             }
-            $data = include($filename);
-            \flock($fp, \LOCK_UN);
-            \fclose($fp);
-            return $data;
+
+            return include($filename);
         } catch (\Throwable) {
             return null;
+        } finally {
+            $lock === false or \flock($fp, \LOCK_UN);
+            $fp === false or \fclose($fp);
         }
     }