diff --git a/services/updateserver/joomla.go b/services/updateserver/joomla.go
index 82febe9615..73fd674613 100644
--- a/services/updateserver/joomla.go
+++ b/services/updateserver/joomla.go
@@ -383,12 +383,12 @@ func GenerateJoomlaXML(ctx context.Context, repo *repo_model.Repository, require
 			infoURL = meta.SupportURL
 		}
 
-		// Joomla <client> element: 0 = site, 1 = administrator.
-		// Packages, components, libraries, and files are admin-side.
-		client := "0"
+		// Joomla <client> element uses string values per the update server spec.
+		// Joomla's XML parser maps these to client_id internally (0/1).
+		client := "site"
 		switch extType {
 		case "package", "component", "library", "file":
-			client = "1"
+			client = "administrator"
 		}
 
 		u := xmlUpdate{