diff --git a/src/public/app/widgets/floating_buttons/toggle_read_only_button.ts b/src/public/app/widgets/floating_buttons/toggle_read_only_button.ts
index 37a99217e..f436c820c 100644
--- a/src/public/app/widgets/floating_buttons/toggle_read_only_button.ts
+++ b/src/public/app/widgets/floating_buttons/toggle_read_only_button.ts
@@ -41,6 +41,7 @@ export default class ToggleReadOnlyButton extends OnClickButtonWidget {
     isEnabled() {
         return super.isEnabled()
             && this.note?.type === "mermaid"
+            && this.note?.isContentAvailable()
             && this.noteContext?.viewScope?.viewMode === "default";
     }