diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7662e8..7db0d83 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 - Memoization for substring generator is done across instances.
 - Memoization for truncator is done across instances.
 - Coder does no longer have memoization.
+- Coder can no longer be instantiated.
 
 ### Fixed
 - Capitalizer discarded empty strings.
diff --git a/src/Formatter/Coder.php b/src/Formatter/Coder.php
index 162b8ed..03d5001 100644
--- a/src/Formatter/Coder.php
+++ b/src/Formatter/Coder.php
@@ -8,10 +8,8 @@
 use Stadly\PasswordPolice\CodeMap;
 use Stadly\PasswordPolice\Formatter;
 
-class Coder implements Formatter
+abstract class Coder implements Formatter
 {
-    use Chaining;
-
     /**
      * @var CodeMap Code map for coding character trees.
      */
@@ -29,10 +27,7 @@ public function __construct(CodeMap $codeMap)
      * @param CharTree $charTree Character tree to format.
      * @return CharTree Coded variant of the character tree.
      */
-    protected function applyCurrent(CharTree $charTree): CharTree
-    {
-        return $this->format($charTree);
-    }
+    abstract protected function applyCurrent(CharTree $charTree): CharTree;
 
     /**
      * @param CharTree $charTree Character tree to format.
diff --git a/tests/Formatter/CoderClass.php b/tests/Formatter/CoderClass.php
new file mode 100644
index 0000000..513005e
--- /dev/null
+++ b/tests/Formatter/CoderClass.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stadly\PasswordPolice\Formatter;
+
+use Stadly\PasswordPolice\CharTree;
+
+final class CoderClass extends Coder
+{
+    use Chaining;
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function applyCurrent(CharTree $charTree): CharTree
+    {
+        return $this->format($charTree);
+    }
+}
diff --git a/tests/Formatter/CoderTest.php b/tests/Formatter/CoderTest.php
index ea82a20..8e3b49a 100644
--- a/tests/Formatter/CoderTest.php
+++ b/tests/Formatter/CoderTest.php
@@ -44,7 +44,7 @@ static function (CharTree $charTree): array {
      */
     public function testCanFormatEmptyCharacterTree(): void
     {
-        $formatter = new Coder($this->codeMap);
+        $formatter = new CoderClass($this->codeMap);
 
         self::assertSame(CharTree::fromArray([
         ]), $formatter->apply(CharTree::fromArray([
@@ -56,7 +56,7 @@ public function testCanFormatEmptyCharacterTree(): void
      */
     public function testCanFormatEmptyStringCharacterTree(): void
     {
-        $formatter = new Coder($this->codeMap);
+        $formatter = new CoderClass($this->codeMap);
 
         self::assertSame(CharTree::fromArray([
             CharTree::fromString(''),
@@ -70,7 +70,7 @@ public function testCanFormatEmptyStringCharacterTree(): void
      */
     public function testCanFormatCharacterPath(): void
     {
-        $formatter = new Coder($this->codeMap);
+        $formatter = new CoderClass($this->codeMap);
 
         self::assertSame(CharTree::fromArray([
             CharTree::fromString('gPpCbS'),
@@ -84,7 +84,7 @@ public function testCanFormatCharacterPath(): void
      */
     public function testCanFormatCharacterTree(): void
     {
-        $formatter = new Coder($this->codeMap);
+        $formatter = new CoderClass($this->codeMap);
 
         self::assertSame(CharTree::fromArray([
             CharTree::fromString('gPp'),
@@ -104,7 +104,7 @@ public function testCanFormatCharacterTree(): void
      */
     public function testCanApplyFormatterChain(): void
     {
-        $formatter = new Coder($this->codeMap);
+        $formatter = new CoderClass($this->codeMap);
 
         $next = $this->createMock(Formatter::class);
         $next->method('apply')->willReturnCallback(