diff --git a/packages/block-editor/src/components/block-pattern-setup/style.scss b/packages/block-editor/src/components/block-pattern-setup/style.scss
index c3e2cb82d66a5..da362df93a7e5 100644
--- a/packages/block-editor/src/components/block-pattern-setup/style.scss
+++ b/packages/block-editor/src/components/block-pattern-setup/style.scss
@@ -38,6 +38,7 @@
 
 			.block-editor-block-preview__container {
 				border-radius: $radius-block-ui;
+				border: $border-width solid $gray-300;
 			}
 		}
 	}
@@ -79,6 +80,7 @@
 		display: flex;
 		flex-direction: column;
 		width: 100%;
+		box-sizing: border-box;
 
 		.carousel-container {
 			overflow: hidden;