diff --git a/src/mentionui.js b/src/mentionui.js
index 96df6deedcebf00ad089835301383022337ace1c..a45f6ddc9c195a40faf6a034266402e2a7993ccd 100644
--- a/src/mentionui.js
+++ b/src/mentionui.js
@@ -529,7 +529,6 @@ export function createRegExp(marker, minimumCharacters) {
     // When "u" flag is used, the regexp has "strict" escaping rules, i.e. if you try to escape a character that does not need
     // to be escaped, RegExp() will throw. It made it difficult to write a generic util, because different characters are
     // allowed in different context. For example, escaping "-" sometimes was correct, but sometimes it threw an error.
-    marker = marker.replace(/[.*+?^${}()\-|[\]\\]/g, '\\$&');
     // The pattern consists of 3 groups:
     //
     // - 0 (non-capturing): Opening sequence - start of the line, space or an opening punctuation character like "(" or "\"",
@@ -538,7 +537,7 @@ export function createRegExp(marker, minimumCharacters) {
     //
     // The pattern matches up to the caret (end of string switch - $).
     //               (0:      opening sequence       )(1:   marker  )(2:                typed mention              )$
-    const pattern = `(?:^|[ ${openAfterCharacters}])([${marker}])(${mentionCharacters}${numberOfCharacters})$`;
+    const pattern = `(?:^|[= ${ openAfterCharacters }])([${ marker }])([${ mentionCharacters }]${ numberOfCharacters })$`;
     return new RegExp(pattern, 'u');
 }
 /**