diff --git a/src/components/chat/ChatIframe.tsx b/src/components/chat/ChatIframe.tsx
index 56a29a523..ba2d1ee09 100644
--- a/src/components/chat/ChatIframe.tsx
+++ b/src/components/chat/ChatIframe.tsx
@@ -63,6 +63,8 @@ function generateGrillConfig(entity: ChatEntity['entity']): GrillConfig | null {
       hub: {
         id: COMMENTS_HUB_ID,
       },
+      theme: 'light',
+      rootFontSize: '1rem',
       channel: {
         type: 'resource',
         resource: new Resource({