Ticket #3359: 3359.diff

wordcamp.org/public_html/wp-content/mu-plugins/gutenberg-tweaks.php

@@ -84 +84 @@
         <script type="text/javascript">
                 document.addEventListener( 'DOMContentLoaded', function() {
                         jQuery( '.split-page-title-action' ).children( 'a' ).each( function( index, element ) {
-                                jQuery( element ).attr( 'href', jQuery( element ).attr( 'href' ) + '&classic-editor' );
+                                var href = jQuery( element ).attr( 'href' );
+                                if ( href.match(/.php$/) ) {
+                                        jQuery( element ).attr( 'href', href + '?classic-editor' );
+                                } else {
+                                        jQuery( element ).attr( 'href', href + '&classic-editor' );
+                                }
                         } );
                 } );
         </script>