diff --git a/.changeset/weak-hotels-shout.md b/.changeset/weak-hotels-shout.md
new file mode 100644
index 00000000000..48b0be09f5d
--- /dev/null
+++ b/.changeset/weak-hotels-shout.md
@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+MarkdownViewer bug fix: Only run `replaceChildren` when `htmlContainer` changes
diff --git a/src/drafts/MarkdownViewer/MarkdownViewer.tsx b/src/drafts/MarkdownViewer/MarkdownViewer.tsx
index 5e0b0afa8f3..209ecd4274a 100644
--- a/src/drafts/MarkdownViewer/MarkdownViewer.tsx
+++ b/src/drafts/MarkdownViewer/MarkdownViewer.tsx
@@ -107,7 +107,7 @@ const MarkdownViewer = ({
   // If we were to inject the `...htmlContainer.children` instead of the container element itself,
   // those children elements would be moved from the `htmlContainer` to the `outputContainer`. Then if
   // other effects use `htmlContainer.querySelectorAll`, they wouldn't find any elements to affect
-  useEffect(() => outputContainerRef.current?.replaceChildren(htmlContainer))
+  useEffect(() => outputContainerRef.current?.replaceChildren(htmlContainer), [htmlContainer])
 
   return loading ? (
     <Box sx={{display: 'flex', justifyContent: 'space-around', p: 2}}>