diff --git a/tests/phpunit/tests/query/commentFeed.php b/tests/phpunit/tests/query/commentFeed.php
new file mode 100644
index 0000000000..2deda2df40
--- /dev/null
+++ b/tests/phpunit/tests/query/commentFeed.php
@@ -0,0 +1,112 @@
+<?php
+
+/**
+ * @group query
+ * @group comments
+ * @group feeds
+ */
+class Tests_Query_CommentFeed extends WP_UnitTestCase {
+	public static $post_type   = 'post';
+	protected static $post_ids = array();
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$post_ids = $factory->post->create_many(
+			3,
+			array(
+				'post_type'   => self::$post_type,
+				'post_status' => 'publish',
+			)
+		);
+		foreach ( self::$post_ids as $post_id ) {
+			$factory->comment->create_post_comments( $post_id, 5 );
+		}
+
+		update_option( 'posts_per_rss', 100 );
+	}
+
+	/**
+	 * @ticket 36904
+	 */
+	public function test_archive_comment_feed() {
+		global $wpdb;
+		add_filter( 'split_the_query', '__return_false' );
+		$q1   = new WP_Query();
+		$args = array(
+			'withcomments'           => 1,
+			'feed'                   => 'comments-rss',
+			'post_type'              => self::$post_type,
+			'update_post_meta_cache' => false,
+			'update_post_term_cache' => false,
+			'ignore_sticky_posts'    => false,
+			'no_found_rows'          => true,
+		);
+		$q1->query( $args );
+		$num_queries = $wpdb->num_queries;
+		$q2          = new WP_Query();
+		$q2->query( $args );
+		$this->assertTrue( $q2->is_comment_feed() );
+		$this->assertFalse( $q2->is_singular() );
+		$this->assertSame( $num_queries + 1, $wpdb->num_queries );
+	}
+
+	/**
+	 * @ticket 36904
+	 */
+	public function test_archive_comment_feed_invalid_cache() {
+		$q1   = new WP_Query();
+		$args = array(
+			'withcomments'           => 1,
+			'feed'                   => 'comments-rss',
+			'post_type'              => self::$post_type,
+			'update_post_meta_cache' => false,
+			'update_post_term_cache' => false,
+			'ignore_sticky_posts'    => false,
+		);
+		$q1->query( $args );
+		$comment_count = $q1->comment_count;
+		$this->assertSame( 15, $comment_count );
+
+		$post = self::factory()->post->create_and_get(
+			array(
+				'post_type'   => self::$post_type,
+				'post_status' => 'publish',
+			)
+		);
+		self::factory()->comment->create_post_comments( $post->ID, 5 );
+		$q2 = new WP_Query();
+		$q2->query( $args );
+		$this->assertTrue( $q2->is_comment_feed() );
+		$this->assertFalse( $q2->is_singular() );
+
+		$comment_count = $q2->comment_count;
+		$this->assertSame( 20, $comment_count );
+	}
+
+	/**
+	 * @ticket 36904
+	 */
+	public function test_single_comment_feed() {
+		global $wpdb;
+		$post = get_post( self::$post_ids[0] );
+
+		$q1   = new WP_Query();
+		$args = array(
+			'withcomments'           => 1,
+			'feed'                   => 'comments-rss',
+			'post_type'              => $post->post_type,
+			'name'                   => $post->post_name,
+			'update_post_meta_cache' => false,
+			'update_post_term_cache' => false,
+			'ignore_sticky_posts'    => false,
+		);
+
+		$q1->query( $args );
+		$num_queries = $wpdb->num_queries;
+		$q2          = new WP_Query();
+		$q2->query( $args );
+
+		$this->assertTrue( $q2->is_comment_feed() );
+		$this->assertTrue( $q2->is_singular() );
+		$this->assertSame( $num_queries + 1, $wpdb->num_queries );
+	}
+}