diff --git a/.changeset/yellow-seas-attend.md b/.changeset/yellow-seas-attend.md
new file mode 100644
index 00000000..9b985a11
--- /dev/null
+++ b/.changeset/yellow-seas-attend.md
@@ -0,0 +1,5 @@
+---
+'@matrix-widget-toolkit/mui': patch
+---
+
+Prevent leak of colorHash prop to the DOM when using an avatar
diff --git a/packages/mui/src/components/ElementAvatar/ElementAvatar.tsx b/packages/mui/src/components/ElementAvatar/ElementAvatar.tsx
index 03457a8e..fbb4e245 100644
--- a/packages/mui/src/components/ElementAvatar/ElementAvatar.tsx
+++ b/packages/mui/src/components/ElementAvatar/ElementAvatar.tsx
@@ -86,7 +86,7 @@ export type ElementAvatarProps = {
 } & AvatarProps;
 
 const StyledAvatar = styled(Avatar, {
-  shouldForwardProp: (p) => p !== 'color',
+  shouldForwardProp: (p: string) => !['color', 'colorHash'].includes(p),
 })<{ colorHash: number }>(({ theme, colorHash }) => ({
   // increase the specificity of the css selector to override styles of
   // chip or button components that provide their own css for avatars.