diff --git a/Common/UI/Components/Markdown.tsx/MarkdownViewer.tsx b/Common/UI/Components/Markdown.tsx/MarkdownViewer.tsx
index 7fe3235338..63a9cfe7ff 100644
--- a/Common/UI/Components/Markdown.tsx/MarkdownViewer.tsx
+++ b/Common/UI/Components/Markdown.tsx/MarkdownViewer.tsx
@@ -35,7 +35,7 @@ const MermaidDiagram: FunctionComponent<{ chart: string }> = ({
 }: {
   chart: string;
 }) => {
-  const containerRef: React.RefObject<HTMLDivElement | null> =
+  const containerRef: React.RefObject<HTMLDivElement> =
     useRef<HTMLDivElement>(null);
 
   useEffect(() => {