diff --git a/src/BinaryReader.php b/src/BinaryReader.php
index edb13e0..241eb33 100644
--- a/src/BinaryReader.php
+++ b/src/BinaryReader.php
@@ -4,7 +4,7 @@
 
 use RuntimeException;
 
-class BinaryReader
+final class BinaryReader
 {
     private string $_data;
 
diff --git a/src/BinaryString.php b/src/BinaryString.php
index ae098c2..18e0e7b 100644
--- a/src/BinaryString.php
+++ b/src/BinaryString.php
@@ -2,7 +2,7 @@
 
 namespace KDuma\BinaryTools;
 
-readonly class BinaryString
+final readonly class BinaryString
 {
     protected function __construct(public string $value)
     {
diff --git a/src/BinaryWriter.php b/src/BinaryWriter.php
index c9312f0..0b41a53 100644
--- a/src/BinaryWriter.php
+++ b/src/BinaryWriter.php
@@ -2,7 +2,7 @@
 
 namespace KDuma\BinaryTools;
 
-class BinaryWriter
+final class BinaryWriter
 {
     private string $buffer = '';