diff --git a/cloudstack/BackupService.go b/cloudstack/BackupService.go
index 1a00485..92033d8 100644
--- a/cloudstack/BackupService.go
+++ b/cloudstack/BackupService.go
@@ -922,8 +922,7 @@ func (p *CreateVMFromBackupParams) toURLValues() url.Values {
 	if v, found := p.p["userdatadetails"]; found {
 		m := v.(map[string]string)
 		for i, k := range getSortedKeysFromMap(m) {
-			u.Set(fmt.Sprintf("userdatadetails[%d].key", i), k)
-			u.Set(fmt.Sprintf("userdatadetails[%d].value", i), m[k])
+			u.Set(fmt.Sprintf("userdatadetails[%d].%s", i, k), m[k])
 		}
 	}
 	if v, found := p.p["userdataid"]; found {