diff --git a/lib/BaseViewer.d.ts b/lib/BaseViewer.d.ts
index 7cb0adde..c293103c 100644
--- a/lib/BaseViewer.d.ts
+++ b/lib/BaseViewer.d.ts
@@ -272,7 +272,7 @@ export default class BaseViewer extends Diagram {
    *
    * @return A promise resolving with the XML.
    */
-  saveXML(options: SaveXMLOptions): Promise<SaveXMLResult>;
+  saveXML(options?: SaveXMLOptions): Promise<SaveXMLResult>;
 
   /**
    * Export the currently displayed BPMN 2.0 diagram as
diff --git a/lib/BaseViewer.spec.ts b/lib/BaseViewer.spec.ts
index 69d351a0..21b6456f 100644
--- a/lib/BaseViewer.spec.ts
+++ b/lib/BaseViewer.spec.ts
@@ -89,6 +89,10 @@ export function testViewer(viewer: BaseViewer) {
       console.log(error);
     });
 
+  viewer.saveXML();
+
+  viewer.saveSVG();
+
   viewer.getModules();
 
   viewer.clear();