diff --git a/UPGRADING.md b/UPGRADING.md
index f148dd72ab4..4a5a9f4b847 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -507,6 +507,59 @@
 	- [BC] Class `Psalm\Issue\ParseError` became final
 	- [BC] Class `Psalm\Issue\PossiblyUndefinedStringArrayOffset` became final
 	- [BC] Class `Psalm\Issue\ExtensionRequirementViolation` became final
+ - Storage classes became final:
+	- [BC] Class `Psalm\Storage\MethodStorage` became final
+	- [BC] Class `Psalm\Storage\AttributeStorage` became final
+	- [BC] Class `Psalm\Storage\FileStorage` became final
+	- [BC] Class `Psalm\Storage\PropertyStorage` became final
+	- [BC] Class `Psalm\Storage\FunctionStorage` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasArrayKey` became final
+	- [BC] Class `Psalm\Storage\Assertion\Truthy` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsAClass` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasAtLeastCount` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasMethod` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasIntOrStringArrayAccess` became final
+	- [BC] Class `Psalm\Storage\Assertion\DoesNotHaveMethod` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsLessThanOrEqualTo` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotAClass` became final
+	- [BC] Class `Psalm\Storage\Assertion\ArrayKeyDoesNotExist` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotIdentical` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsClassEqual` became final
+	- [BC] Class `Psalm\Storage\Assertion\NotNonEmptyCountable` became final
+	- [BC] Class `Psalm\Storage\Assertion\Any` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsLooselyEqual` became final
+	- [BC] Class `Psalm\Storage\Assertion\NonEmpty` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsGreaterThanOrEqualTo` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasStringArrayAccess` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsClassNotEqual` became final
+	- [BC] Class `Psalm\Storage\Assertion\HasExactCount` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotCountable` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsIdentical` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsType` became final
+	- [BC] Class `Psalm\Storage\Assertion\NotNestedAssertions` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsGreaterThan` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsIsset` became final
+	- [BC] Class `Psalm\Storage\Assertion\Empty_` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotType` became final
+	- [BC] Class `Psalm\Storage\Assertion\ArrayKeyExists` became final
+	- [BC] Class `Psalm\Storage\Assertion\DoesNotHaveAtLeastCount` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotIsset` became final
+	- [BC] Class `Psalm\Storage\Assertion\NonEmptyCountable` became final
+	- [BC] Class `Psalm\Storage\Assertion\NestedAssertions` became final
+	- [BC] Class `Psalm\Storage\Assertion\Falsy` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsNotLooselyEqual` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsEqualIsset` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsLessThan` became final
+	- [BC] Class `Psalm\Storage\Assertion\DoesNotHaveExactCount` became final
+	- [BC] Class `Psalm\Storage\Assertion\IsCountable` became final
+	- [BC] Class `Psalm\Storage\Assertion\NotInArray` became final
+	- [BC] Class `Psalm\Storage\Assertion\InArray` became final
+	- [BC] Class `Psalm\Storage\FunctionLikeParameter` became final
+	- [BC] Class `Psalm\Storage\Possibilities` became final
+	- [BC] Class `Psalm\Storage\ClassConstantStorage` became final
+	- [BC] Class `Psalm\Storage\ClassLikeStorage` became final
+	- [BC] Class `Psalm\Storage\AttributeArg` became final
+	- [BC] Class `Psalm\Storage\EnumCaseStorage` became final
 
 ## Removed
  - [BC] Property `Psalm\Codebase::$php_major_version` was removed, use
@@ -564,4 +617,3 @@
    - :information_source: migration possible using `Psalm\PluginFileExtensionsSocket`
  - [BC] Method `\Psalm\Plugin\EventHandler\Event\AfterFunctionLikeAnalysisEvent::getClasslikeStorage()` was removed,
    use correct `\Psalm\Plugin\EventHandler\Event\AfterFunctionLikeAnalysisEvent::getFunctionlikeStorage()` instead
-
diff --git a/src/Psalm/Storage/Assertion/Any.php b/src/Psalm/Storage/Assertion/Any.php
index 6256e0a5f64..4aab3fda16a 100644
--- a/src/Psalm/Storage/Assertion/Any.php
+++ b/src/Psalm/Storage/Assertion/Any.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class Any extends Assertion
+final class Any extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/ArrayKeyDoesNotExist.php b/src/Psalm/Storage/Assertion/ArrayKeyDoesNotExist.php
index f174a7fea8e..43a6f0bd557 100644
--- a/src/Psalm/Storage/Assertion/ArrayKeyDoesNotExist.php
+++ b/src/Psalm/Storage/Assertion/ArrayKeyDoesNotExist.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class ArrayKeyDoesNotExist extends Assertion
+final class ArrayKeyDoesNotExist extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/ArrayKeyExists.php b/src/Psalm/Storage/Assertion/ArrayKeyExists.php
index 598a5b9bd84..0b803cd4dd9 100644
--- a/src/Psalm/Storage/Assertion/ArrayKeyExists.php
+++ b/src/Psalm/Storage/Assertion/ArrayKeyExists.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class ArrayKeyExists extends Assertion
+final class ArrayKeyExists extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/DoesNotHaveAtLeastCount.php b/src/Psalm/Storage/Assertion/DoesNotHaveAtLeastCount.php
index a64c52c509b..297e61ddb83 100644
--- a/src/Psalm/Storage/Assertion/DoesNotHaveAtLeastCount.php
+++ b/src/Psalm/Storage/Assertion/DoesNotHaveAtLeastCount.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class DoesNotHaveAtLeastCount extends Assertion
+final class DoesNotHaveAtLeastCount extends Assertion
 {
     /** @var positive-int */
     public $count;
diff --git a/src/Psalm/Storage/Assertion/DoesNotHaveExactCount.php b/src/Psalm/Storage/Assertion/DoesNotHaveExactCount.php
index 4a4eb645f89..950bf72eba6 100644
--- a/src/Psalm/Storage/Assertion/DoesNotHaveExactCount.php
+++ b/src/Psalm/Storage/Assertion/DoesNotHaveExactCount.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class DoesNotHaveExactCount extends Assertion
+final class DoesNotHaveExactCount extends Assertion
 {
     /** @var positive-int */
     public $count;
diff --git a/src/Psalm/Storage/Assertion/DoesNotHaveMethod.php b/src/Psalm/Storage/Assertion/DoesNotHaveMethod.php
index 1a80432ba5c..eef48187543 100644
--- a/src/Psalm/Storage/Assertion/DoesNotHaveMethod.php
+++ b/src/Psalm/Storage/Assertion/DoesNotHaveMethod.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class DoesNotHaveMethod extends Assertion
+final class DoesNotHaveMethod extends Assertion
 {
     public string $method;
 
diff --git a/src/Psalm/Storage/Assertion/Empty_.php b/src/Psalm/Storage/Assertion/Empty_.php
index 6dced7aa8f6..91613b0f4a2 100644
--- a/src/Psalm/Storage/Assertion/Empty_.php
+++ b/src/Psalm/Storage/Assertion/Empty_.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class Empty_ extends Assertion
+final class Empty_ extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/Falsy.php b/src/Psalm/Storage/Assertion/Falsy.php
index 81e139a0d86..13c85088eeb 100644
--- a/src/Psalm/Storage/Assertion/Falsy.php
+++ b/src/Psalm/Storage/Assertion/Falsy.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class Falsy extends Assertion
+final class Falsy extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/HasArrayKey.php b/src/Psalm/Storage/Assertion/HasArrayKey.php
index 168357daca8..7442c4a39a7 100644
--- a/src/Psalm/Storage/Assertion/HasArrayKey.php
+++ b/src/Psalm/Storage/Assertion/HasArrayKey.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use UnexpectedValueException;
 
-class HasArrayKey extends Assertion
+final class HasArrayKey extends Assertion
 {
     public $key;
 
diff --git a/src/Psalm/Storage/Assertion/HasAtLeastCount.php b/src/Psalm/Storage/Assertion/HasAtLeastCount.php
index 699823a8302..46ec83abfeb 100644
--- a/src/Psalm/Storage/Assertion/HasAtLeastCount.php
+++ b/src/Psalm/Storage/Assertion/HasAtLeastCount.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class HasAtLeastCount extends Assertion
+final class HasAtLeastCount extends Assertion
 {
     /** @var positive-int */
     public $count;
diff --git a/src/Psalm/Storage/Assertion/HasExactCount.php b/src/Psalm/Storage/Assertion/HasExactCount.php
index 777e74fce95..36d0400c29c 100644
--- a/src/Psalm/Storage/Assertion/HasExactCount.php
+++ b/src/Psalm/Storage/Assertion/HasExactCount.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class HasExactCount extends Assertion
+final class HasExactCount extends Assertion
 {
     /** @var positive-int */
     public $count;
diff --git a/src/Psalm/Storage/Assertion/HasIntOrStringArrayAccess.php b/src/Psalm/Storage/Assertion/HasIntOrStringArrayAccess.php
index 63bd651e5d9..88620c8b0f8 100644
--- a/src/Psalm/Storage/Assertion/HasIntOrStringArrayAccess.php
+++ b/src/Psalm/Storage/Assertion/HasIntOrStringArrayAccess.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use UnexpectedValueException;
 
-class HasIntOrStringArrayAccess extends Assertion
+final class HasIntOrStringArrayAccess extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/HasMethod.php b/src/Psalm/Storage/Assertion/HasMethod.php
index de99013a2e4..94508472404 100644
--- a/src/Psalm/Storage/Assertion/HasMethod.php
+++ b/src/Psalm/Storage/Assertion/HasMethod.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class HasMethod extends Assertion
+final class HasMethod extends Assertion
 {
     public string $method;
 
diff --git a/src/Psalm/Storage/Assertion/HasStringArrayAccess.php b/src/Psalm/Storage/Assertion/HasStringArrayAccess.php
index b0251c026d8..d7595287857 100644
--- a/src/Psalm/Storage/Assertion/HasStringArrayAccess.php
+++ b/src/Psalm/Storage/Assertion/HasStringArrayAccess.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use UnexpectedValueException;
 
-class HasStringArrayAccess extends Assertion
+final class HasStringArrayAccess extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/InArray.php b/src/Psalm/Storage/Assertion/InArray.php
index fcc127e0347..b5e1abc2ea7 100644
--- a/src/Psalm/Storage/Assertion/InArray.php
+++ b/src/Psalm/Storage/Assertion/InArray.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Union;
 
-class InArray extends Assertion
+final class InArray extends Assertion
 {
     public Union $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsAClass.php b/src/Psalm/Storage/Assertion/IsAClass.php
index 83b056abbab..3b6c5473952 100644
--- a/src/Psalm/Storage/Assertion/IsAClass.php
+++ b/src/Psalm/Storage/Assertion/IsAClass.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsAClass extends Assertion
+final class IsAClass extends Assertion
 {
     /** @var Atomic\TTemplateParamClass|Atomic\TNamedObject */
     public Atomic $type;
diff --git a/src/Psalm/Storage/Assertion/IsClassEqual.php b/src/Psalm/Storage/Assertion/IsClassEqual.php
index 307b399b9e4..da5307aa7f5 100644
--- a/src/Psalm/Storage/Assertion/IsClassEqual.php
+++ b/src/Psalm/Storage/Assertion/IsClassEqual.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsClassEqual extends Assertion
+final class IsClassEqual extends Assertion
 {
     public string $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsClassNotEqual.php b/src/Psalm/Storage/Assertion/IsClassNotEqual.php
index 39241ac2508..c8d05dc8b77 100644
--- a/src/Psalm/Storage/Assertion/IsClassNotEqual.php
+++ b/src/Psalm/Storage/Assertion/IsClassNotEqual.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsClassNotEqual extends Assertion
+final class IsClassNotEqual extends Assertion
 {
     public string $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsCountable.php b/src/Psalm/Storage/Assertion/IsCountable.php
index 543921d808c..dea9295b28c 100644
--- a/src/Psalm/Storage/Assertion/IsCountable.php
+++ b/src/Psalm/Storage/Assertion/IsCountable.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsCountable extends Assertion
+final class IsCountable extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/IsEqualIsset.php b/src/Psalm/Storage/Assertion/IsEqualIsset.php
index 0ac2e9af920..bded7c5ce06 100644
--- a/src/Psalm/Storage/Assertion/IsEqualIsset.php
+++ b/src/Psalm/Storage/Assertion/IsEqualIsset.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsEqualIsset extends Assertion
+final class IsEqualIsset extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/IsGreaterThan.php b/src/Psalm/Storage/Assertion/IsGreaterThan.php
index 96ba74aa396..131c3fc94a9 100644
--- a/src/Psalm/Storage/Assertion/IsGreaterThan.php
+++ b/src/Psalm/Storage/Assertion/IsGreaterThan.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsGreaterThan extends Assertion
+final class IsGreaterThan extends Assertion
 {
     public int $value;
 
diff --git a/src/Psalm/Storage/Assertion/IsGreaterThanOrEqualTo.php b/src/Psalm/Storage/Assertion/IsGreaterThanOrEqualTo.php
index 5cf032ae063..ce8590eafc8 100644
--- a/src/Psalm/Storage/Assertion/IsGreaterThanOrEqualTo.php
+++ b/src/Psalm/Storage/Assertion/IsGreaterThanOrEqualTo.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsGreaterThanOrEqualTo extends Assertion
+final class IsGreaterThanOrEqualTo extends Assertion
 {
     public int $value;
 
diff --git a/src/Psalm/Storage/Assertion/IsIdentical.php b/src/Psalm/Storage/Assertion/IsIdentical.php
index 9d29d5b59f7..9f6dccfae10 100644
--- a/src/Psalm/Storage/Assertion/IsIdentical.php
+++ b/src/Psalm/Storage/Assertion/IsIdentical.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsIdentical extends Assertion
+final class IsIdentical extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsIsset.php b/src/Psalm/Storage/Assertion/IsIsset.php
index dda04c24f32..7b5fd06423b 100644
--- a/src/Psalm/Storage/Assertion/IsIsset.php
+++ b/src/Psalm/Storage/Assertion/IsIsset.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsIsset extends Assertion
+final class IsIsset extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/IsLessThan.php b/src/Psalm/Storage/Assertion/IsLessThan.php
index ab797dac228..0f26f5c53e1 100644
--- a/src/Psalm/Storage/Assertion/IsLessThan.php
+++ b/src/Psalm/Storage/Assertion/IsLessThan.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsLessThan extends Assertion
+final class IsLessThan extends Assertion
 {
     public int $value;
 
diff --git a/src/Psalm/Storage/Assertion/IsLessThanOrEqualTo.php b/src/Psalm/Storage/Assertion/IsLessThanOrEqualTo.php
index 82dc9d65732..36afbe8e282 100644
--- a/src/Psalm/Storage/Assertion/IsLessThanOrEqualTo.php
+++ b/src/Psalm/Storage/Assertion/IsLessThanOrEqualTo.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsLessThanOrEqualTo extends Assertion
+final class IsLessThanOrEqualTo extends Assertion
 {
     public int $value;
 
diff --git a/src/Psalm/Storage/Assertion/IsLooselyEqual.php b/src/Psalm/Storage/Assertion/IsLooselyEqual.php
index 33cfccd9320..35b1e6d6259 100644
--- a/src/Psalm/Storage/Assertion/IsLooselyEqual.php
+++ b/src/Psalm/Storage/Assertion/IsLooselyEqual.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsLooselyEqual extends Assertion
+final class IsLooselyEqual extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsNotAClass.php b/src/Psalm/Storage/Assertion/IsNotAClass.php
index 1ac2b5166ac..45cbd3442ef 100644
--- a/src/Psalm/Storage/Assertion/IsNotAClass.php
+++ b/src/Psalm/Storage/Assertion/IsNotAClass.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsNotAClass extends Assertion
+final class IsNotAClass extends Assertion
 {
     /** @var Atomic\TTemplateParamClass|Atomic\TNamedObject */
     public Atomic $type;
diff --git a/src/Psalm/Storage/Assertion/IsNotCountable.php b/src/Psalm/Storage/Assertion/IsNotCountable.php
index 615269bbb36..b09a7a7dcdc 100644
--- a/src/Psalm/Storage/Assertion/IsNotCountable.php
+++ b/src/Psalm/Storage/Assertion/IsNotCountable.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsNotCountable extends Assertion
+final class IsNotCountable extends Assertion
 {
     public $is_negatable;
 
diff --git a/src/Psalm/Storage/Assertion/IsNotIdentical.php b/src/Psalm/Storage/Assertion/IsNotIdentical.php
index 9c9ab732eb5..2c023300a02 100644
--- a/src/Psalm/Storage/Assertion/IsNotIdentical.php
+++ b/src/Psalm/Storage/Assertion/IsNotIdentical.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsNotIdentical extends Assertion
+final class IsNotIdentical extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsNotIsset.php b/src/Psalm/Storage/Assertion/IsNotIsset.php
index 4bb32b24cc1..defa8479a32 100644
--- a/src/Psalm/Storage/Assertion/IsNotIsset.php
+++ b/src/Psalm/Storage/Assertion/IsNotIsset.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class IsNotIsset extends Assertion
+final class IsNotIsset extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/IsNotLooselyEqual.php b/src/Psalm/Storage/Assertion/IsNotLooselyEqual.php
index f1fd889a777..bcf77c78514 100644
--- a/src/Psalm/Storage/Assertion/IsNotLooselyEqual.php
+++ b/src/Psalm/Storage/Assertion/IsNotLooselyEqual.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsNotLooselyEqual extends Assertion
+final class IsNotLooselyEqual extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsNotType.php b/src/Psalm/Storage/Assertion/IsNotType.php
index ddad7757231..321dd744e0c 100644
--- a/src/Psalm/Storage/Assertion/IsNotType.php
+++ b/src/Psalm/Storage/Assertion/IsNotType.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsNotType extends Assertion
+final class IsNotType extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/IsType.php b/src/Psalm/Storage/Assertion/IsType.php
index 3f305d548b1..2c822a79d40 100644
--- a/src/Psalm/Storage/Assertion/IsType.php
+++ b/src/Psalm/Storage/Assertion/IsType.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Atomic;
 
-class IsType extends Assertion
+final class IsType extends Assertion
 {
     public Atomic $type;
 
diff --git a/src/Psalm/Storage/Assertion/NestedAssertions.php b/src/Psalm/Storage/Assertion/NestedAssertions.php
index 9e74e04725b..c7fa0a48e62 100644
--- a/src/Psalm/Storage/Assertion/NestedAssertions.php
+++ b/src/Psalm/Storage/Assertion/NestedAssertions.php
@@ -8,7 +8,7 @@
 
 use const JSON_THROW_ON_ERROR;
 
-class NestedAssertions extends Assertion
+final class NestedAssertions extends Assertion
 {
     /** @var array<string, list<list<Assertion>>> */
     public array $assertions;
diff --git a/src/Psalm/Storage/Assertion/NonEmpty.php b/src/Psalm/Storage/Assertion/NonEmpty.php
index 785c3388ee9..bb662d9591f 100644
--- a/src/Psalm/Storage/Assertion/NonEmpty.php
+++ b/src/Psalm/Storage/Assertion/NonEmpty.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class NonEmpty extends Assertion
+final class NonEmpty extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/NonEmptyCountable.php b/src/Psalm/Storage/Assertion/NonEmptyCountable.php
index 9990e348035..c42eca24d57 100644
--- a/src/Psalm/Storage/Assertion/NonEmptyCountable.php
+++ b/src/Psalm/Storage/Assertion/NonEmptyCountable.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class NonEmptyCountable extends Assertion
+final class NonEmptyCountable extends Assertion
 {
     public $is_negatable;
 
diff --git a/src/Psalm/Storage/Assertion/NotInArray.php b/src/Psalm/Storage/Assertion/NotInArray.php
index 138786bb02e..2dbbb71161b 100644
--- a/src/Psalm/Storage/Assertion/NotInArray.php
+++ b/src/Psalm/Storage/Assertion/NotInArray.php
@@ -5,7 +5,7 @@
 use Psalm\Storage\Assertion;
 use Psalm\Type\Union;
 
-class NotInArray extends Assertion
+final class NotInArray extends Assertion
 {
     public Union $type;
 
diff --git a/src/Psalm/Storage/Assertion/NotNestedAssertions.php b/src/Psalm/Storage/Assertion/NotNestedAssertions.php
index f594bd22ae6..ad6f46f9ef6 100644
--- a/src/Psalm/Storage/Assertion/NotNestedAssertions.php
+++ b/src/Psalm/Storage/Assertion/NotNestedAssertions.php
@@ -8,7 +8,7 @@
 
 use const JSON_THROW_ON_ERROR;
 
-class NotNestedAssertions extends Assertion
+final class NotNestedAssertions extends Assertion
 {
     /** @var array<string, list<list<Assertion>>> */
     public array $assertions;
diff --git a/src/Psalm/Storage/Assertion/NotNonEmptyCountable.php b/src/Psalm/Storage/Assertion/NotNonEmptyCountable.php
index 2e7cf3e8224..d4a59fbd1a6 100644
--- a/src/Psalm/Storage/Assertion/NotNonEmptyCountable.php
+++ b/src/Psalm/Storage/Assertion/NotNonEmptyCountable.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class NotNonEmptyCountable extends Assertion
+final class NotNonEmptyCountable extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/Assertion/Truthy.php b/src/Psalm/Storage/Assertion/Truthy.php
index 78ba516899c..1d92be6e158 100644
--- a/src/Psalm/Storage/Assertion/Truthy.php
+++ b/src/Psalm/Storage/Assertion/Truthy.php
@@ -4,7 +4,7 @@
 
 use Psalm\Storage\Assertion;
 
-class Truthy extends Assertion
+final class Truthy extends Assertion
 {
     /** @psalm-mutation-free */
     public function getNegation(): Assertion
diff --git a/src/Psalm/Storage/AttributeArg.php b/src/Psalm/Storage/AttributeArg.php
index 510fe06c7e7..7d15a214a70 100644
--- a/src/Psalm/Storage/AttributeArg.php
+++ b/src/Psalm/Storage/AttributeArg.php
@@ -6,7 +6,7 @@
 use Psalm\Internal\Scanner\UnresolvedConstantComponent;
 use Psalm\Type\Union;
 
-class AttributeArg
+final class AttributeArg
 {
     /**
      * @var ?string
diff --git a/src/Psalm/Storage/AttributeStorage.php b/src/Psalm/Storage/AttributeStorage.php
index 3fe6b9bb1eb..b07d922222e 100644
--- a/src/Psalm/Storage/AttributeStorage.php
+++ b/src/Psalm/Storage/AttributeStorage.php
@@ -4,7 +4,7 @@
 
 use Psalm\CodeLocation;
 
-class AttributeStorage
+final class AttributeStorage
 {
     /**
      * @var string
diff --git a/src/Psalm/Storage/ClassConstantStorage.php b/src/Psalm/Storage/ClassConstantStorage.php
index e1cd077fe06..61705fb77b4 100644
--- a/src/Psalm/Storage/ClassConstantStorage.php
+++ b/src/Psalm/Storage/ClassConstantStorage.php
@@ -10,7 +10,7 @@
 /**
  * @psalm-suppress PossiblyUnusedProperty
  */
-class ClassConstantStorage
+final class ClassConstantStorage
 {
     use CustomMetadataTrait;
 
diff --git a/src/Psalm/Storage/ClassLikeStorage.php b/src/Psalm/Storage/ClassLikeStorage.php
index 381f9c912a2..4d924e1b0b7 100644
--- a/src/Psalm/Storage/ClassLikeStorage.php
+++ b/src/Psalm/Storage/ClassLikeStorage.php
@@ -11,7 +11,7 @@
 use Psalm\Type\Atomic\TTemplateParam;
 use Psalm\Type\Union;
 
-class ClassLikeStorage
+final class ClassLikeStorage
 {
     use CustomMetadataTrait;
 
diff --git a/src/Psalm/Storage/EnumCaseStorage.php b/src/Psalm/Storage/EnumCaseStorage.php
index c61fcea3d24..24ec0791399 100644
--- a/src/Psalm/Storage/EnumCaseStorage.php
+++ b/src/Psalm/Storage/EnumCaseStorage.php
@@ -4,7 +4,7 @@
 
 use Psalm\CodeLocation;
 
-class EnumCaseStorage
+final class EnumCaseStorage
 {
     /**
      * @var int|string|null
diff --git a/src/Psalm/Storage/FileStorage.php b/src/Psalm/Storage/FileStorage.php
index df09117dbea..aebb14d192f 100644
--- a/src/Psalm/Storage/FileStorage.php
+++ b/src/Psalm/Storage/FileStorage.php
@@ -7,7 +7,7 @@
 use Psalm\Issue\CodeIssue;
 use Psalm\Type\Union;
 
-class FileStorage
+final class FileStorage
 {
     use CustomMetadataTrait;
 
diff --git a/src/Psalm/Storage/FunctionLikeParameter.php b/src/Psalm/Storage/FunctionLikeParameter.php
index 261b203a3c7..1e60d086e5a 100644
--- a/src/Psalm/Storage/FunctionLikeParameter.php
+++ b/src/Psalm/Storage/FunctionLikeParameter.php
@@ -6,7 +6,7 @@
 use Psalm\Internal\Scanner\UnresolvedConstantComponent;
 use Psalm\Type\Union;
 
-class FunctionLikeParameter
+final class FunctionLikeParameter
 {
     use CustomMetadataTrait;
 
diff --git a/src/Psalm/Storage/FunctionStorage.php b/src/Psalm/Storage/FunctionStorage.php
index 22be01b0a11..e39e7cc2356 100644
--- a/src/Psalm/Storage/FunctionStorage.php
+++ b/src/Psalm/Storage/FunctionStorage.php
@@ -2,7 +2,7 @@
 
 namespace Psalm\Storage;
 
-class FunctionStorage extends FunctionLikeStorage
+final class FunctionStorage extends FunctionLikeStorage
 {
     /** @var array<string, bool> */
     public $byref_uses = [];
diff --git a/src/Psalm/Storage/MethodStorage.php b/src/Psalm/Storage/MethodStorage.php
index f9ae6a2777d..5a9e59e3642 100644
--- a/src/Psalm/Storage/MethodStorage.php
+++ b/src/Psalm/Storage/MethodStorage.php
@@ -4,7 +4,7 @@
 
 use Psalm\Type\Union;
 
-class MethodStorage extends FunctionLikeStorage
+final class MethodStorage extends FunctionLikeStorage
 {
     /**
      * @var bool
diff --git a/src/Psalm/Storage/Possibilities.php b/src/Psalm/Storage/Possibilities.php
index 72a7a882ff9..c526881800f 100644
--- a/src/Psalm/Storage/Possibilities.php
+++ b/src/Psalm/Storage/Possibilities.php
@@ -10,7 +10,7 @@
 use function is_string;
 use function str_replace;
 
-class Possibilities
+final class Possibilities
 {
     /**
      * @var list<Assertion> the rule being asserted
diff --git a/src/Psalm/Storage/PropertyStorage.php b/src/Psalm/Storage/PropertyStorage.php
index 7fdc14f7ad8..08ad69bdd90 100644
--- a/src/Psalm/Storage/PropertyStorage.php
+++ b/src/Psalm/Storage/PropertyStorage.php
@@ -6,7 +6,7 @@
 use Psalm\Internal\Analyzer\ClassLikeAnalyzer;
 use Psalm\Type\Union;
 
-class PropertyStorage
+final class PropertyStorage
 {
     use CustomMetadataTrait;