diff --git a/tests/phpunit/tests/option/sanitize-option.php b/tests/phpunit/tests/option/sanitize-option.php
index ccf2301f13..9c69c0e49a 100644
--- a/tests/phpunit/tests/option/sanitize-option.php
+++ b/tests/phpunit/tests/option/sanitize-option.php
@@ -70,7 +70,7 @@ class Tests_Sanitize_Option extends WP_UnitTestCase {
 			array( 'timezone_string', 'Europe/London', 'Europe/London' ),
 			array( 'timezone_string', get_option( 'timezone_string' ), 'invalid' ),
 			array( 'permalink_structure', '', '' ),
-			array( 'permalink_structure', '/%year%/%postname%', '/%year%/ %postname%' ),
+			array( 'permalink_structure', '/%year%/%20%postname%', '/%year%/ %postname%' ),
 			array( 'default_role', 'subscriber', 'subscriber' ),
 			array( 'default_role', 'subscriber', 'invalid' ),
 			array( 'default_role', 'editor', 'editor' ),