diff --git a/src/ExtendableAttributesTrait.php b/src/ExtendableAttributesTrait.php
index af5090a..eda2b60 100644
--- a/src/ExtendableAttributesTrait.php
+++ b/src/ExtendableAttributesTrait.php
@@ -89,11 +89,11 @@ public function getAttributesNS(): array
      * NOTE: In case the namespace is ##any, this method will also return local non-namespaced attributes!
      *
      * @param \DOMElement $xml
-     * @param string|array|null $namespace
+     * @param \SimpleSAML\XML\XsNamespace|array|null $namespace
      *
      * @return list<\SimpleSAML\XML\Attribute> $attributes
      */
-    protected static function getAttributesNSFromXML(DOMElement $xml, string|array $namespace = null): array
+    protected static function getAttributesNSFromXML(DOMElement $xml, NS|array $namespace = null): array
     {
         $namespace = $namespace ?? static::XS_ANY_ATTR_NAMESPACE;
         $attributes = [];
diff --git a/src/Utils/XPath.php b/src/Utils/XPath.php
index ac0f3ad..c7203db 100644
--- a/src/Utils/XPath.php
+++ b/src/Utils/XPath.php
@@ -49,7 +49,7 @@ public static function getXPath(DOMNode $node): DOMXPath
      * @param \DOMNode $node  The XML node.
      * @param string $query The query.
      * @param \DOMXPath $xpCache The DOMXPath object
-     * @return \DOMNode[] Array with matching DOM nodes.
+     * @return array<int<0, max>, \DOMNameSpaceNode|\DOMNode|null> Array with matching DOM nodes.
      */
     public static function xpQuery(DOMNode $node, string $query, DOMXPath $xpCache): array
     {
diff --git a/tests/Utils/ExtendableAttributesElement.php b/tests/Utils/ExtendableAttributesElement.php
index 368d657..faebdbd 100644
--- a/tests/Utils/ExtendableAttributesElement.php
+++ b/tests/Utils/ExtendableAttributesElement.php
@@ -31,7 +31,7 @@ class ExtendableAttributesElement extends AbstractElement
     /** @var string */
     public const LOCALNAME = 'ExtendableAttributesElement';
 
-    /** @var string|array */
+    /** @var string|\SimpleSAML\XML\XsNamespace */
     public const XS_ANY_ATTR_NAMESPACE = NS::ANY;