diff --git a/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js b/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
index 8209ba4109..17bda8861a 100644
--- a/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
+++ b/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
@@ -131,10 +131,9 @@ tinymce.PluginManager.add( 'wordpress', function( editor ) {
 			}
 
 			// Remove spaces from empty paragraphs.
-			// Avoid backtracking, can freeze the editor. See #35890.
-			// (This is also quite faster than using only one regex.)
+			// Try to avoid a lot of backtracking, can freeze the editor. See #35890 and #38294.
 			event.content = event.content.replace( /<p>([^<>]+)<\/p>/gi, function( tag, text ) {
-				if ( /^(&nbsp;|\s|\u00a0|\ufeff)+$/i.test( text ) ) {
+				if ( text === '&nbsp;' || ! /\S/.test( text ) ) {
 					return '<p><br /></p>';
 				}