diff --git a/app/code/core/Mage/Core/Helper/UnserializeArray.php b/app/code/core/Mage/Core/Helper/UnserializeArray.php
index d81119d0873..42a48606d0e 100644
--- a/app/code/core/Mage/Core/Helper/UnserializeArray.php
+++ b/app/code/core/Mage/Core/Helper/UnserializeArray.php
@@ -26,11 +26,13 @@ class Mage_Core_Helper_UnserializeArray
      * @param string $str
      * @return array
      * @throws Exception
+     * @SuppressWarnings("PHPMD.ErrorControlOperator")
      */
     public function unserialize($str)
     {
         try {
-            $result = unserialize($str, ['allowed_classes' => false]);
+            $str = is_null($str) ? '' : $str;
+            $result = @unserialize($str, ['allowed_classes' => false]);
             if ($result === false && $str !== serialize(false)) {
                 throw new Exception('Error unserializing data.');
             }
diff --git a/tests/unit/Mage/Core/Helper/UnserializeArrayTest.php b/tests/unit/Mage/Core/Helper/UnserializeArrayTest.php
index 8803897b14a..458e49c1f42 100644
--- a/tests/unit/Mage/Core/Helper/UnserializeArrayTest.php
+++ b/tests/unit/Mage/Core/Helper/UnserializeArrayTest.php
@@ -50,16 +50,18 @@ public function testUnserialize($expectedTesult, $string): void
 
     public function provideUnserialize(): Generator
     {
+        $errorMessage = 'Error unserializing data.';
+
         yield 'null' => [
-            'Error unserializing data.',
+            $errorMessage,
             null,
         ];
         yield 'empty string' => [
-            'Error unserializing data.',
+            $errorMessage,
             '',
         ];
         yield 'random string' => [
-            'unserialize(): Error at offset 0 of 3 bytes',
+            $errorMessage,
             'abc',
         ];
         yield 'valid' => [