diff --git a/packages/block-editor/src/components/inserter/index.js b/packages/block-editor/src/components/inserter/index.js
index 47304a7d771747..59d78a6f0edc6c 100644
--- a/packages/block-editor/src/components/inserter/index.js
+++ b/packages/block-editor/src/components/inserter/index.js
@@ -60,6 +60,7 @@ const defaultRenderToggle = ( {
 
 	return (
 		<Wrapper
+			__next40pxDefaultSize={ toggleProps.as ? undefined : true }
 			icon={ plus }
 			label={ label }
 			tooltipPosition="bottom"