diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
index c51915a97421c..61342d3d8fd63 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -3007,6 +3007,7 @@ public function get_collection_params() {
 				'slug',
 				'include_slugs',
 				'title',
+				'comment_count',
 			),
 		);
 
diff --git a/tests/qunit/fixtures/wp-api-generated.js b/tests/qunit/fixtures/wp-api-generated.js
index f87397b20a449..14b1dec79c432 100644
--- a/tests/qunit/fixtures/wp-api-generated.js
+++ b/tests/qunit/fixtures/wp-api-generated.js
@@ -402,7 +402,8 @@ mockedApiResponse.Schema = {
                                 "relevance",
                                 "slug",
                                 "include_slugs",
-                                "title"
+                                "title",
+                                "comment_count"
                             ],
                             "required": false
                         },
@@ -1795,6 +1796,7 @@ mockedApiResponse.Schema = {
                                 "slug",
                                 "include_slugs",
                                 "title",
+                                "comment_count",
                                 "menu_order"
                             ],
                             "required": false
@@ -2903,7 +2905,8 @@ mockedApiResponse.Schema = {
                                 "relevance",
                                 "slug",
                                 "include_slugs",
-                                "title"
+                                "title",
+                                "comment_count"
                             ],
                             "required": false
                         },
@@ -4481,7 +4484,8 @@ mockedApiResponse.Schema = {
                                 "relevance",
                                 "slug",
                                 "include_slugs",
-                                "title"
+                                "title",
+                                "comment_count"
                             ],
                             "required": false
                         },
@@ -7102,7 +7106,8 @@ mockedApiResponse.Schema = {
                                 "relevance",
                                 "slug",
                                 "include_slugs",
-                                "title"
+                                "title",
+                                "comment_count"
                             ],
                             "required": false
                         },