diff --git a/server/shell.ts b/server/shell.ts
index cc8da49..1bb714e 100644
--- a/server/shell.ts
+++ b/server/shell.ts
@@ -91,7 +91,7 @@ export function renderShell(opts: ShellOptions): string {
   <div class="rstack-tab-row" data-theme="${theme}">
     <rstack-tab-bar space="${escapeAttr(spaceSlug)}" active="" view-mode="flat"></rstack-tab-bar>
   </div>
-  <main id="app">
+  <main id="app"${moduleId === "rspace" ? ' class="canvas-layout"' : ''}>
     ${body}
   </main>