diff --git tests/phpunit/tests/link.php tests/phpunit/tests/link.php
index 1de3f68..13c6d11 100644
--- tests/phpunit/tests/link.php
+++ tests/phpunit/tests/link.php
@@ -286,4 +286,35 @@ class Tests_Link extends WP_UnitTestCase {
 		$relative_link = wp_make_link_relative( $link );
 		$this->assertEquals( '/this-is-a-test/?redirect=https://example.org/a-different-test-post/', $relative_link );
 	}
+
+	/**
+	 * @ticket 28026
+	 */
+	function test_same_date_posts_sort_by_id() {
+		// Need some sample posts to test adjacency
+		$post_one = $this->factory->post->create_and_get( array(
+			'post_title' => 'First',
+			'post_date' => '2012-01-01 12:00:00'
+		) );
+
+		$post_two = $this->factory->post->create_and_get( array(
+			'post_title' => 'Second',
+			'post_date' => '2012-02-01 12:00:00'
+		) );
+
+		$post_three = $this->factory->post->create_and_get( array(
+			'post_title' => 'Third',
+			'post_date' => '2012-02-01 12:00:00'
+		) );
+
+		// Test equal date post adjacency
+		$this->go_to( get_permalink( $post_two->ID ) );
+
+		$this->assertEquals( $post_one, get_adjacent_post( false, '', true ) );
+
+		$this->go_to( get_permalink( $post_three->ID ) );
+
+		$this->assertEquals( $post_two, get_adjacent_post( false, '', true ) );
+
+	}
 }