Index: src/wp-includes/post.php
===================================================================
--- src/wp-includes/post.php	(revision 37161)
+++ src/wp-includes/post.php	(working copy)
@@ -6126,11 +6126,11 @@
 
 	$post = get_post( $post );
 
-	if ( strpos( $post->post_name, '-%trashed%' ) ) {
+	if ( strpos( $post->post_name, '-_trashed' ) ) {
 		return $post->post_name;
 	}
 	add_post_meta( $post->ID, '_wp_desired_post_slug', $post->post_name );
-	$post_name = _truncate_post_slug( $post->post_name, 190 ) . '-%trashed%';
+	$post_name = _truncate_post_slug( $post->post_name, 190 ) . '-_trashed';
 	$wpdb->update( $wpdb->posts, array( 'post_name' => $post_name ), array( 'ID' => $post->ID ) );
 	clean_post_cache( $post->ID );
 	return $post_name;
Index: tests/phpunit/tests/post/wpInsertPost.php
===================================================================
--- tests/phpunit/tests/post/wpInsertPost.php	(revision 37161)
+++ tests/phpunit/tests/post/wpInsertPost.php	(working copy)
@@ -15,7 +15,7 @@
 			'post_status' => 'publish'
 		) );
 		wp_trash_post( $trashed_about_page_id );
-		$this->assertEquals( 'about-%trashed%', get_post( $trashed_about_page_id )->post_name );
+		$this->assertEquals( 'about-_trashed', get_post( $trashed_about_page_id )->post_name );
 	}
 
 	/**
@@ -49,7 +49,7 @@
 			'post_status' => 'publish'
 		) );
 
-		$this->assertEquals( 'about-%trashed%', get_post( $trashed_about_page_id )->post_name );
+		$this->assertEquals( 'about-_trashed', get_post( $trashed_about_page_id )->post_name );
 		$this->assertEquals( 'about', get_post( $about_page_id )->post_name );
 	}