diff --git a/UserPhraseEditor/StringExtension.swift b/UserPhraseEditor/StringExtension.swift
index 8ab7384d..fc3ca498 100644
--- a/UserPhraseEditor/StringExtension.swift
+++ b/UserPhraseEditor/StringExtension.swift
@@ -20,9 +20,10 @@ import Foundation
 
 extension String {
     mutating func regReplace(pattern: String, replaceWith: String = "") {
+        // Ref: https://stackoverflow.com/a/40993403/4162914 && https://stackoverflow.com/a/71291137/4162914
         do {
             let regex = try NSRegularExpression(pattern: pattern, options: .caseInsensitive)
-            let range = NSRange(location: 0, length: count)
+            let range = NSRange(location: 0, length: self.utf16.count)
             self = regex.stringByReplacingMatches(in: self, options: [], range: range, withTemplate: replaceWith)
         } catch { return }
     }