diff --git a/os/include/util/xml_node.h b/os/include/util/xml_node.h
index c6d4b40297..397f2177c2 100644
--- a/os/include/util/xml_node.h
+++ b/os/include/util/xml_node.h
@@ -120,6 +120,11 @@ namespace Genode {
 						return strlen(type) == _name.len() &&
 						       strcmp(type, _name.start(), _name.len()) == 0; }
 
+					/**
+					 * Return size of value
+					 */
+					size_t value_size() const { return _value.len(); }
+
 					/**
 					 * Return attribute value as null-terminated string
 					 *