diff --git a/src/CleanCode/MaxLineLengthRule.php b/src/CleanCode/MaxLineLengthRule.php
index 04d24f8..82fae5b 100644
--- a/src/CleanCode/MaxLineLengthRule.php
+++ b/src/CleanCode/MaxLineLengthRule.php
@@ -324,7 +324,7 @@ private function readFileLineLengths(string $filePath): array
             $lineNumber = $index + 1;
             // Remove carriage return if present and count actual characters
             $line = rtrim($line, "\r");
-            $lineLengths[$lineNumber] = strlen($line);
+            $lineLengths[$lineNumber] = mb_strlen($line);
         }
 
         return $lineLengths;