diff --git a/lib/SimpleSAML/Metadata/MetaDataStorageHandlerMDX.php b/lib/SimpleSAML/Metadata/MetaDataStorageHandlerMDX.php
index 6047b7725b779c4753916083aae45b0f7b84d371..c06a9e04b2ccef96ffa036f51e00a2b8e16b2597 100644
--- a/lib/SimpleSAML/Metadata/MetaDataStorageHandlerMDX.php
+++ b/lib/SimpleSAML/Metadata/MetaDataStorageHandlerMDX.php
@@ -298,6 +298,7 @@ class SimpleSAML_Metadata_MetaDataStorageHandlerMDX extends SimpleSAML_Metadata_
             );
         }
 
+        /** @var string $xmldata */
         $entity = SimpleSAML_Metadata_SAMLParser::parseString($xmldata);
         SimpleSAML_Logger::debug('MetaData - Handler.MDX: Completed parsing of ['.$mdx_url.']');