diff --git a/ecs.php b/ecs.php
index dd04801..60847c7 100644
--- a/ecs.php
+++ b/ecs.php
@@ -134,6 +134,7 @@
 use PhpCsFixer\Fixer\Strict\DeclareStrictTypesFixer;
 use PhpCsFixer\Fixer\Strict\StrictParamFixer;
 use PhpCsFixer\Fixer\StringNotation\SingleQuoteFixer;
+use PhpCsFixer\Fixer\Whitespace\ArrayIndentationFixer;
 use PhpCsFixer\Fixer\Whitespace\BlankLineBeforeStatementFixer;
 use PhpCsFixer\Fixer\Whitespace\CompactNullableTypeDeclarationFixer;
 use PhpCsFixer\Fixer\Whitespace\HeredocIndentationFixer;
@@ -382,6 +383,8 @@
             StrictParamFixer::class,
             // Convert double quotes to single quotes for simple strings
             SingleQuoteFixer::class,
+            // Each element of an array must be indented exactly once.
+            ArrayIndentationFixer::class,
             // Remove extra spaces in a nullable typehint
             CompactNullableTypeDeclarationFixer::class,
             // Heredoc/nowdoc content must be properly indented.
diff --git a/tests/Integration/Fixtures/Basic.correct.php.inc b/tests/Integration/Fixtures/Basic.correct.php.inc
index 52131b0..8d38f7e 100644
--- a/tests/Integration/Fixtures/Basic.correct.php.inc
+++ b/tests/Integration/Fixtures/Basic.correct.php.inc
@@ -64,12 +64,18 @@ class Basic
         $singleLineArray = ['foo', 'bar', 'baz'];
         $singleLineArray2 = [1, 2, 3];
 
-        $multiLineAssociative = [
+        $multiLineAssociative1 = [
             'foo' => 'bar',
             'baz' => 'bat',
         ];
 
         $multiLineAssociative2 = [
+            'foo' => 'bar',
+            'baz' => 'bat',
+            'bak' => 'baz',
+        ];
+
+        $multiLineAssociative3 = [
             'firstKey' => 'bar',
             'thisIsSecondKey' => 'bat',
             'third' => 'bat',
diff --git a/tests/Integration/Fixtures/Basic.wrong.php.inc b/tests/Integration/Fixtures/Basic.wrong.php.inc
index f0909aa..7af2533 100644
--- a/tests/Integration/Fixtures/Basic.wrong.php.inc
+++ b/tests/Integration/Fixtures/Basic.wrong.php.inc
@@ -61,12 +61,17 @@ class Basic
         $singleLineArray = ['foo', 'bar', 'baz',];
         $singleLineArray2 = [1,2,3];
 
-        $multiLineAssociative = [
-            'foo'=>'bar',
-            'baz'=>'bat'
+        $multiLineAssociative1 = [
+            'foo' => 'bar', 'baz' => 'bat',
         ];
 
         $multiLineAssociative2 = [
+            'foo'=>'bar',
+                'baz'=>'bat',
+        'bak'=>'baz'
+        ];
+
+        $multiLineAssociative3 = [
             'firstKey'        => 'bar',
             'thisIsSecondKey' => 'bat',
             'third'           => 'bat',