diff --git a/src/SAML2/Constants.php b/src/SAML2/Constants.php
index d24a32090..f5c77462c 100644
--- a/src/SAML2/Constants.php
+++ b/src/SAML2/Constants.php
@@ -237,6 +237,11 @@ class Constants extends \SimpleSAML\XMLSecurity\Constants
      */
     public const NAMEID_X509_SUBJECT_NAME = 'urn:oasis:names:tc:SAML:1.1:nameid-format:X509SubjectName';
 
+    /**
+     * The namespace for the SAML 2 metadata Algorithm Support profile
+     */
+    public const NS_ALG = 'urn:oasis:names:tc:SAML:metadata:algsupport';
+
     /**
      * The namespace for the ECP protocol.
      */
diff --git a/src/SAML2/XML/alg/AbstractAlgElement.php b/src/SAML2/XML/alg/AbstractAlgElement.php
index 033764799..84e46509f 100644
--- a/src/SAML2/XML/alg/AbstractAlgElement.php
+++ b/src/SAML2/XML/alg/AbstractAlgElement.php
@@ -4,6 +4,7 @@
 
 namespace SimpleSAML\SAML2\XML\alg;
 
+use SAML2\Constants as C;
 use SimpleSAML\XML\AbstractElement;
 
 /**
@@ -14,7 +15,7 @@
 abstract class AbstractAlgElement extends AbstractElement
 {
     /** @var string */
-    public const NS = 'urn:oasis:names:tc:SAML:metadata:algsupport';
+    public const NS = C::NS_ALG;
 
     /** @var string */
     public const NS_PREFIX = 'alg';