diff --git a/packages/mermaid/src/tests/MockedD3.ts b/packages/mermaid/src/tests/MockedD3.ts
index 4e31d98b6..d0d67773f 100644
--- a/packages/mermaid/src/tests/MockedD3.ts
+++ b/packages/mermaid/src/tests/MockedD3.ts
@@ -104,7 +104,9 @@ export class MockedD3 {
   // This allows different tests to succeed -- some need a top level 'svg' and some need a 'svg' element to be the firstChild
   // Real implementation returns an HTML Element
   public node = vi.fn().mockImplementation(() => {
+    //create a top level svg element
     const topElem = this._containingHTMLdoc.createElement('svg');
+    //@ts-ignore - this is a mock SVG element
     topElem.getBBox = this.getBBox;
     const elem_svgChild = this._containingHTMLdoc.createElement('svg'); // another svg element
     topElem.appendChild(elem_svgChild);