diff --git a/lib/src/escape_regexp.dart b/lib/src/escape_regexp.dart
index 107d2dc..1707f69 100644
--- a/lib/src/escape_regexp.dart
+++ b/lib/src/escape_regexp.dart
@@ -1,8 +1,9 @@
-String reRegExpChar = '[\\^\$.*+?()[\]{}|]';
+String reRegExpChar = r'[\\^\$.*+?\(\)\[\]\{\}|]';
 RegExp reHasRegExpChar = RegExp(reRegExpChar);
 
 escapeRegExp(String string) {
   return string.isNotEmpty && reHasRegExpChar.hasMatch(string)
-      ? string.replaceAll(reRegExpChar, '\\\$&')
+      ? string.replaceAllMapped(
+          reHasRegExpChar, (match) => '\\${match.group(0)}')
       : string;
 }