diff --git a/src/util/virxml.c b/src/util/virxml.c
index 9929064993..707a6a2235 100644
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -762,6 +762,7 @@ virXMLPropUInt(xmlNodePtr node,
  * @result: The returned value
  *
  * Convenience function to return value of an unsigned long long attribute.
+ * @result is initialized to 0 on error or if the element is not found.
  *
  * Returns 1 in case of success in which case @result is set,
  *         or 0 if the attribute is not present,
@@ -778,6 +779,8 @@ virXMLPropULongLong(xmlNodePtr node,
     int ret;
     unsigned long long val;
 
+    *result = 0;
+
     if (!(tmp = virXMLPropString(node, name))) {
         if (!(flags & VIR_XML_PROP_REQUIRED))
             return 0;