diff --git a/packages/block-library/src/post-comments-form/block.json b/packages/block-library/src/post-comments-form/block.json
index ff157beb5ced9..af893ccb67a08 100644
--- a/packages/block-library/src/post-comments-form/block.json
+++ b/packages/block-library/src/post-comments-form/block.json
@@ -37,6 +37,18 @@
 			"__experimentalDefaultControls": {
 				"fontSize": true
 			}
+		},
+		"__experimentalBorder": {
+			"radius": true,
+			"color": true,
+			"width": true,
+			"style": true,
+			"__experimentalDefaultControls": {
+				"radius": true,
+				"color": true,
+				"width": true,
+				"style": true
+			}
 		}
 	},
 	"editorStyle": "wp-block-post-comments-form-editor",