diff --git a/CHANGELOG.md b/CHANGELOG.md
index 03eea3d..3222641 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## 0.3.1 Under development
 
+- chore: skip `HeredocIndentationFixer` class to preserve heredoc alignment.
+
 ## 0.3.0 May 05, 2026
 
 - feat!: ship `ecs.php` and `rector.php` wrappers from `src/config/` via `scaffold.json`; metadata moves to `php-forge/baseline`.
diff --git a/src/ecs.php b/src/ecs.php
index bdfd7d9..84df174 100644
--- a/src/ecs.php
+++ b/src/ecs.php
@@ -9,6 +9,7 @@
 use PhpCsFixer\Fixer\PhpUnit\PhpUnitTestCaseStaticMethodCallsFixer;
 use PhpCsFixer\Fixer\Strict\{DeclareStrictTypesFixer, StrictComparisonFixer, StrictParamFixer};
 use PhpCsFixer\Fixer\StringNotation\SingleQuoteFixer;
+use PhpCsFixer\Fixer\Whitespace\HeredocIndentationFixer;
 use Symplify\EasyCodingStandard\Config\ECSConfig;
 
 /**
@@ -26,15 +27,11 @@
 return ECSConfig::configure()
     ->withConfiguredRule(
         ClassDefinitionFixer::class,
-        [
-            'space_before_parenthesis' => true,
-        ],
+        ['space_before_parenthesis' => true],
     )
     ->withConfiguredRule(
         NullableTypeDeclarationFixer::class,
-        [
-            'syntax' => 'union',
-        ],
+        ['syntax' => 'union'],
     )
     ->withConfiguredRule(
         OrderedClassElementsFixer::class,
@@ -80,9 +77,7 @@
     )
     ->withConfiguredRule(
         PhpUnitTestCaseStaticMethodCallsFixer::class,
-        [
-            'call_type' => 'self',
-        ],
+        ['call_type' => 'self'],
     )
     ->withFileExtensions(['php'])
     ->withPhpCsFixerSets(perCS30: true)
@@ -101,4 +96,7 @@
             StrictComparisonFixer::class,
             StrictParamFixer::class,
         ],
+    )
+    ->withSkip(
+        [HeredocIndentationFixer::class],
     );