diff --git a/src/Parser/Filter/NodeName.php b/src/Parser/Filter/NodeName.php
index de16f349..8b59a639 100644
--- a/src/Parser/Filter/NodeName.php
+++ b/src/Parser/Filter/NodeName.php
@@ -75,7 +75,9 @@ public function setOptions(array $options)
             $this->excludePattern = (string) $options['excludePattern'];
         }
 
-        if (isset($options['namespaceFilter'])) {
+        if (isset($options['namespaceFilter'])
+            && $options['namespaceFilter'] instanceof NamespaceFilterInterface
+        ) {
             $this->namespaceFilter = $options['namespaceFilter'];
         }
     }