diff --git a/module/Core/functions/functions.php b/module/Core/functions/functions.php
index 6ae232be..c766b767 100644
--- a/module/Core/functions/functions.php
+++ b/module/Core/functions/functions.php
@@ -10,6 +10,9 @@ use Fig\Http\Message\StatusCodeInterface;
 use Laminas\InputFilter\InputFilter;
 use PUGX\Shortid\Factory as ShortIdFactory;
 
+use function Functional\reduce_left;
+use function is_array;
+use function print_r;
 use function sprintf;
 
 const DEFAULT_DELETE_SHORT_URL_THRESHOLD = 15;
@@ -75,3 +78,12 @@ function getOptionalBoolFromInputFilter(InputFilter $inputFilter, string $fieldN
     $value = $inputFilter->getValue($fieldName);
     return $value !== null ? (bool) $value : null;
 }
+
+function arrayToString(array $array): string
+{
+    return reduce_left($array, fn ($messages, string $name, $_, string $acc) => $acc . sprintf(
+        "\n    '%s' => %s",
+        $name,
+        is_array($messages) ? print_r($messages, true) : $messages,
+    ), '');
+}
diff --git a/module/Core/src/Exception/ValidationException.php b/module/Core/src/Exception/ValidationException.php
index fc090279..195cfa42 100644
--- a/module/Core/src/Exception/ValidationException.php
+++ b/module/Core/src/Exception/ValidationException.php
@@ -11,9 +11,7 @@ use Mezzio\ProblemDetails\Exception\ProblemDetailsExceptionInterface;
 use Throwable;
 
 use function array_keys;
-use function Functional\reduce_left;
-use function is_array;
-use function print_r;
+use function Shlinkio\Shlink\Core\arrayToString;
 use function sprintf;
 
 use const PHP_EOL;
@@ -60,19 +58,10 @@ class ValidationException extends InvalidArgumentException implements ProblemDet
             $this->getMessage(),
             $this->getFile(),
             $this->getLine(),
-            $this->invalidElementsToString(),
+            arrayToString($this->getInvalidElements()),
             PHP_EOL,
             PHP_EOL,
             $this->getTraceAsString(),
         );
     }
-
-    private function invalidElementsToString(): string
-    {
-        return reduce_left($this->getInvalidElements(), fn ($messages, string $name, $_, string $acc) => $acc . sprintf(
-            "\n    '%s' => %s",
-            $name,
-            is_array($messages) ? print_r($messages, true) : $messages,
-        ), '');
-    }
 }
diff --git a/module/Core/test/Exception/ValidationExceptionTest.php b/module/Core/test/Exception/ValidationExceptionTest.php
index 44a46c1f..fab70760 100644
--- a/module/Core/test/Exception/ValidationExceptionTest.php
+++ b/module/Core/test/Exception/ValidationExceptionTest.php
@@ -32,9 +32,9 @@ class ValidationExceptionTest extends TestCase
         ];
         $barValue = print_r(['baz', 'foo'], true);
         $expectedStringRepresentation = <<<EOT
-    'foo' => bar
-    'something' => {$barValue}
-EOT;
+            'foo' => bar
+            'something' => {$barValue}
+        EOT;
 
         $inputFilter = $this->prophesize(InputFilterInterface::class);
         $getMessages = $inputFilter->getMessages()->willReturn($invalidData);