diff --git a/src/corelib/serialization/qxmlstream.cpp b/src/corelib/serialization/qxmlstream.cpp
index 61c9f343ec..f630aa9743 100644
--- a/src/corelib/serialization/qxmlstream.cpp
+++ b/src/corelib/serialization/qxmlstream.cpp
@@ -1812,7 +1812,7 @@ void QXmlStreamReaderPrivate::startDocument()
             else
                 err = QXmlStream::tr("Standalone accepts only yes or no.");
         } else {
-            err = QXmlStream::tr("Invalid attribute in XML declaration.");
+            err = QXmlStream::tr("Invalid attribute in XML declaration: %1 = %2").arg(key).arg(value);
         }
     }