diff --git a/src/Pattern/CallbackCache.php b/src/Pattern/CallbackCache.php
index cc3dd7b0..4a2d7a61 100644
--- a/src/Pattern/CallbackCache.php
+++ b/src/Pattern/CallbackCache.php
@@ -111,6 +111,9 @@ public function generateKey(callable $callback, array $args = []): string
      */
     protected function generateCallbackKey(callable $callback, array $args): string
     {
+        if (! is_callable($callback, false, $callbackKey)) {
+            throw new Exception\InvalidArgumentException('Invalid callback');
+        }
 
         // Create a cache key for the ObjectCache use case.
         $options = $this->getOptions();
@@ -120,9 +123,6 @@ protected function generateCallbackKey(callable $callback, array $args): string
             return $callbackKey . $argumentKey;
         }
 
-        if (! is_callable($callback, false, $callbackKey)) {
-            throw new Exception\InvalidArgumentException('Invalid callback');
-        }
 
         // functions, methods and classnames are case-insensitive
         $callbackKey = strtolower($callbackKey);
diff --git a/test/Pattern/TestAsset/TestObjectCache.php b/test/Pattern/TestAsset/TestObjectCache.php
index ec4e0bda..68f10356 100644
--- a/test/Pattern/TestAsset/TestObjectCache.php
+++ b/test/Pattern/TestAsset/TestObjectCache.php
@@ -4,6 +4,8 @@
 
 namespace LaminasTest\Cache\Pattern\TestAsset;
 
+use Closure;
+
 use function func_get_args;
 use function implode;
 
@@ -22,7 +24,7 @@ final class TestObjectCache
     /** @var string */
     public $property = 'testProperty';
 
-    private \Closure $closure;
+    private Closure $closure;
 
     public function __construct()
     {