diff --git a/src/vmime/net/fetchAttributes.cpp b/src/vmime/net/fetchAttributes.cpp
index 85a41b8c..d499674c 100644
--- a/src/vmime/net/fetchAttributes.cpp
+++ b/src/vmime/net/fetchAttributes.cpp
@@ -60,7 +60,7 @@ fetchAttributes::fetchAttributes(const fetchAttributes& attribs)
 
 void fetchAttributes::add(const int attribs)
 {
-	m_predefinedAttribs = attribs;
+	m_predefinedAttribs |= attribs;
 }