diff --git a/packages/editor/editor.css b/packages/editor/editor.css
index cd814498f..16f19dc7a 100644
--- a/packages/editor/editor.css
+++ b/packages/editor/editor.css
@@ -183,6 +183,7 @@
 	scrollbar-highlight-color: transparent;
 	-webkit-user-select: none;
 	user-select: none;
+	box-sizing: border-box;
 	outline: none;
 }