diff --git a/src/Plugin/Field/FieldWidget/TextFieldCounterWidgetTrait.php b/src/Plugin/Field/FieldWidget/TextFieldCounterWidgetTrait.php
index 49442fe..b98263a 100644
--- a/src/Plugin/Field/FieldWidget/TextFieldCounterWidgetTrait.php
+++ b/src/Plugin/Field/FieldWidget/TextFieldCounterWidgetTrait.php
@@ -378,13 +378,13 @@ trait TextFieldCounterWidgetTrait {
     $count_html_characters = $element['#textfield-count-html'];
 
     if ($count_html_characters) {
-      $value_length = Unicode::strlen($value) - $newline_count;
+      $value_length = mb_strlen($value) - $newline_count;
     }
     else {
       $value_length = str_replace(' ', ' ', $value);
       $value_length = trim($value_length);
       $value_length = preg_replace("/(\r?\n|\r)+/", "\n", $value_length);
-      $value_length = Unicode::strlen(strip_tags($value_length));
+      $value_length = mb_strlen(strip_tags($value_length));
     }
 
     return $value_length;