diff --git a/src/Configuration/Defaults/CommonRules.php b/src/Configuration/Defaults/CommonRules.php
index 19e5bd1..7d6b3ec 100644
--- a/src/Configuration/Defaults/CommonRules.php
+++ b/src/Configuration/Defaults/CommonRules.php
@@ -24,6 +24,7 @@
 use PhpCsFixer\Fixer\Casing\MagicConstantCasingFixer;
 use PhpCsFixer\Fixer\Casing\MagicMethodCasingFixer;
 use PhpCsFixer\Fixer\Casing\NativeFunctionCasingFixer;
+use PhpCsFixer\Fixer\Casing\NativeTypeDeclarationCasingFixer;
 use PhpCsFixer\Fixer\CastNotation\CastSpacesFixer;
 use PhpCsFixer\Fixer\CastNotation\LowercaseCastFixer;
 use PhpCsFixer\Fixer\CastNotation\ShortScalarCastFixer;
@@ -368,6 +369,7 @@ class CommonRules extends Rules
         NoMultilineWhitespaceAroundDoubleArrowFixer::class => true,
         CompactEmptyArrayFixer::class => true,
         ClassKeywordFixer::class => true,
+        NativeTypeDeclarationCasingFixer::class => true,
         NamedArgumentFixer::class => true,
         NoBlankLinesAfterPhpdocFixer::class => true,
         ConstantCaseFixer::class => true,
diff --git a/tests/codestyle/CommonRulesetTest.php b/tests/codestyle/CommonRulesetTest.php
index 581c351..e945fa0 100644
--- a/tests/codestyle/CommonRulesetTest.php
+++ b/tests/codestyle/CommonRulesetTest.php
@@ -48,6 +48,7 @@ public static function providePhp81Fixtures(): array
         return [
             ["enums"],
             ["readonlies"],
+            ["nativeFunctionTypeDeclarations"],
         ];
     }
 
diff --git a/tests/fixtures/enums/actual.php b/tests/fixtures/enums/actual.php
index b063769..d8fae4a 100644
--- a/tests/fixtures/enums/actual.php
+++ b/tests/fixtures/enums/actual.php
@@ -2,6 +2,6 @@
 
 enum Status: string
 {
-    case ACTIVE = "active";
-    case INACTIVE = "inactive";
+    case Active = "active";
+    case Inactive = "inactive";
 }
\ No newline at end of file
diff --git a/tests/fixtures/enums/expected.php b/tests/fixtures/enums/expected.php
index 97647db..a9e377c 100644
--- a/tests/fixtures/enums/expected.php
+++ b/tests/fixtures/enums/expected.php
@@ -4,6 +4,6 @@
 
 enum Status: string
 {
-    case ACTIVE = "active";
-    case INACTIVE = "inactive";
+    case Active = "active";
+    case Inactive = "inactive";
 }
diff --git a/tests/fixtures/nativeFunctionTypeDeclarations/actual.php b/tests/fixtures/nativeFunctionTypeDeclarations/actual.php
new file mode 100644
index 0000000..0dd4d4a
--- /dev/null
+++ b/tests/fixtures/nativeFunctionTypeDeclarations/actual.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+enum Status: String
+{
+    case Active = "active";
+}
+enum Priority: Int
+{
+    case High = 1;
+}
diff --git a/tests/fixtures/nativeFunctionTypeDeclarations/expected.php b/tests/fixtures/nativeFunctionTypeDeclarations/expected.php
new file mode 100644
index 0000000..f190c9a
--- /dev/null
+++ b/tests/fixtures/nativeFunctionTypeDeclarations/expected.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+enum Status: string
+{
+    case Active = "active";
+}
+enum Priority: int
+{
+    case High = 1;
+}