diff --git a/packages/block-library/src/post-comments-link/block.json b/packages/block-library/src/post-comments-link/block.json
index 67831b1d15c5d5..8e23bc7a695070 100644
--- a/packages/block-library/src/post-comments-link/block.json
+++ b/packages/block-library/src/post-comments-link/block.json
@@ -42,6 +42,13 @@
 		},
 		"interactivity": {
 			"clientNavigation": true
+		},
+		"__experimentalBorder": {
+			"radius": true,
+			"color": true,
+			"width": true,
+			"style": true
 		}
-	}
+	},
+	"style": "wp-block-post-comments-link"
 }
diff --git a/packages/block-library/src/post-comments-link/style.scss b/packages/block-library/src/post-comments-link/style.scss
new file mode 100644
index 00000000000000..110179d3ee1df9
--- /dev/null
+++ b/packages/block-library/src/post-comments-link/style.scss
@@ -0,0 +1,4 @@
+.wp-block-post-comments-link {
+	// This block has customizable padding, border-box makes that more predictable.
+	box-sizing: border-box;
+}
diff --git a/packages/block-library/src/style.scss b/packages/block-library/src/style.scss
index 663626caaac87e..c61049c23151b9 100644
--- a/packages/block-library/src/style.scss
+++ b/packages/block-library/src/style.scss
@@ -37,6 +37,7 @@
 @import "./post-author-biography/style.scss";
 @import "./post-comments-form/style.scss";
 @import "./post-content/style.scss";
+@import "./post-comments-link/style.scss";
 @import "./post-date/style.scss";
 @import "./post-excerpt/style.scss";
 @import "./post-featured-image/style.scss";