diff --git a/extension.neon b/extension.neon
index 7808525..aab2056 100644
--- a/extension.neon
+++ b/extension.neon
@@ -69,6 +69,11 @@ services:
         tags:
             - phpstan.ignoreErrorExtension
 
+    -
+        class: Pest\PHPStan\Type\Pest\ArchExpectationPropertyIgnoreExtension
+        tags:
+            - phpstan.ignoreErrorExtension
+
     -
         class: Pest\PHPStan\Type\Pest\TestCallMethodsClassReflectionExtension
         tags:
diff --git a/src/Type/Pest/ArchExpectationPropertyIgnoreExtension.php b/src/Type/Pest/ArchExpectationPropertyIgnoreExtension.php
new file mode 100644
index 0000000..f9e3302
--- /dev/null
+++ b/src/Type/Pest/ArchExpectationPropertyIgnoreExtension.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\PHPStan\Type\Pest;
+
+use Pest\Arch\Contracts\ArchExpectation;
+use PhpParser\Node;
+use PhpParser\Node\Expr\PropertyFetch;
+use PhpParser\Node\Identifier;
+use PHPStan\Analyser\Error;
+use PHPStan\Analyser\IgnoreErrorExtension;
+use PHPStan\Analyser\Scope;
+use PHPStan\Type\ObjectType;
+
+final class ArchExpectationPropertyIgnoreExtension implements IgnoreErrorExtension
+{
+    public function shouldIgnore(Error $error, Node $node, Scope $scope): bool
+    {
+        if ($error->getIdentifier() !== 'property.notFound') {
+            return false;
+        }
+
+        if (! $node instanceof PropertyFetch) {
+            return false;
+        }
+
+        if (! $node->name instanceof Identifier || ! in_array($node->name->name, ExpectationPropertiesExtension::KNOWN_EXPECTATION_PROPERTIES, true)) {
+            return false;
+        }
+
+        return (new ObjectType(ArchExpectation::class))
+            ->isSuperTypeOf($scope->getType($node->var))
+            ->yes();
+    }
+}
diff --git a/src/Type/Pest/ArchExpectationTypeResolver.php b/src/Type/Pest/ArchExpectationTypeResolver.php
new file mode 100644
index 0000000..5916622
--- /dev/null
+++ b/src/Type/Pest/ArchExpectationTypeResolver.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\PHPStan\Type\Pest;
+
+use Pest\Expectation;
+use Pest\Expectations\OppositeExpectation;
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+
+final class ArchExpectationTypeResolver
+{
+    public static function getNotPropertyType(ClassReflection $classReflection): Type
+    {
+        foreach ($classReflection->getResolvedMixinTypes() as $mixinType) {
+            $mixinClassReflections = $mixinType->getObjectClassReflections();
+            foreach ($mixinClassReflections as $mixinClassReflection) {
+                if ($mixinClassReflection->is(Expectation::class)) {
+                    $tValue = $mixinType->getTemplateType(Expectation::class, 'TValue');
+
+                    return new GenericObjectType(OppositeExpectation::class, [$tValue]);
+                }
+            }
+        }
+
+        return new GenericObjectType(OppositeExpectation::class, [new ObjectType('string')]);
+    }
+}
diff --git a/src/Type/Pest/ExpectationPropertiesExtension.php b/src/Type/Pest/ExpectationPropertiesExtension.php
index 322c7b2..a843201 100644
--- a/src/Type/Pest/ExpectationPropertiesExtension.php
+++ b/src/Type/Pest/ExpectationPropertiesExtension.php
@@ -4,6 +4,7 @@
 
 namespace Pest\PHPStan\Type\Pest;
 
+use Pest\Arch\Contracts\ArchExpectation;
 use Pest\Expectation;
 use Pest\Expectations\HigherOrderExpectation;
 use PHPStan\Reflection\ClassReflection;
@@ -14,10 +15,14 @@
 final class ExpectationPropertiesExtension implements PropertiesClassReflectionExtension
 {
     /** @var list<string> */
-    private const KNOWN_EXPECTATION_PROPERTIES = ['not', 'each', 'classes', 'traits', 'interfaces', 'enums', 'value'];
+    public const KNOWN_EXPECTATION_PROPERTIES = ['not', 'each', 'classes', 'traits', 'interfaces', 'enums', 'value'];
 
     public function hasProperty(ClassReflection $classReflection, string $propertyName): bool
     {
+        if ($classReflection->is(ArchExpectation::class) && $propertyName === 'not' && ! $classReflection->hasNativeProperty($propertyName)) {
+            return true;
+        }
+
         if ($classReflection->is(Expectation::class)) {
             return ! in_array($propertyName, self::KNOWN_EXPECTATION_PROPERTIES, true)
                 && ! $classReflection->hasNativeProperty($propertyName);
@@ -32,6 +37,13 @@ public function hasProperty(ClassReflection $classReflection, string $propertyNa
 
     public function getProperty(ClassReflection $classReflection, string $propertyName): PropertyReflection
     {
+        if ($classReflection->is(ArchExpectation::class) && $propertyName === 'not') {
+            return new PestTestCaseProperty(
+                $classReflection,
+                ArchExpectationTypeResolver::getNotPropertyType($classReflection),
+            );
+        }
+
         return new PestTestCaseProperty($classReflection, new MixedType);
     }
 }
diff --git a/src/Type/Pest/HigherOrderExpectationTypeExtension.php b/src/Type/Pest/HigherOrderExpectationTypeExtension.php
index 2f60a95..d6dd825 100644
--- a/src/Type/Pest/HigherOrderExpectationTypeExtension.php
+++ b/src/Type/Pest/HigherOrderExpectationTypeExtension.php
@@ -4,6 +4,7 @@
 
 namespace Pest\PHPStan\Type\Pest;
 
+use Pest\Arch\Contracts\ArchExpectation;
 use Pest\Expectation;
 use Pest\Expectations\HigherOrderExpectation;
 use Pest\Expectations\OppositeExpectation;
@@ -15,6 +16,7 @@
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Type\ExpressionTypeResolverExtension;
 use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
 
@@ -49,6 +51,15 @@ private function resolvePropertyFetch(PropertyFetch $expr, Scope $scope): ?Type
         $propertyName = $expr->name->name;
         $varType = $scope->getType($expr->var);
 
+        if ($propertyName === 'not') {
+            $archType = new ObjectType(ArchExpectation::class);
+            if ($archType->isSuperTypeOf($varType)->yes()) {
+                $valueType = $this->extractTValueFromArchExpectationChain($expr, $scope);
+
+                return new GenericObjectType(OppositeExpectation::class, [$valueType]);
+            }
+        }
+
         $expectationType = new ObjectType(Expectation::class);
         if ($expectationType->isSuperTypeOf($varType)->yes()) {
             return $this->resolveExpectationPropertyFetch($varType, $propertyName, $scope);
@@ -62,6 +73,20 @@ private function resolvePropertyFetch(PropertyFetch $expr, Scope $scope): ?Type
         return null;
     }
 
+    private function extractTValueFromArchExpectationChain(PropertyFetch $expr, Scope $scope): Type
+    {
+        if ($expr->var instanceof MethodCall) {
+            $originalType = $scope->getType($expr->var->var);
+            $tValue = $originalType->getTemplateType(Expectation::class, 'TValue');
+
+            if (! $tValue instanceof MixedType) {
+                return $tValue;
+            }
+        }
+
+        return new ObjectType('string');
+    }
+
     private function resolveExpectationPropertyFetch(Type $varType, string $propertyName, Scope $scope): ?Type
     {
         if ($propertyName === 'not') {
diff --git a/tests/Rules/ArchExpectationNotPropertyIgnoreExtensionTest.php b/tests/Rules/ArchExpectationNotPropertyIgnoreExtensionTest.php
new file mode 100644
index 0000000..3e73911
--- /dev/null
+++ b/tests/Rules/ArchExpectationNotPropertyIgnoreExtensionTest.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Rules;
+
+use PHPStan\Rules\Properties\AccessPropertiesRule;
+use Tests\RuleTestCase;
+
+beforeAll(function (): void {
+    RuleTestCase::$additionalConfigFiles = [
+        __DIR__.'/../extension.neon',
+    ];
+    RuleTestCase::$rule = RuleTestCase::resolveRule(AccessPropertiesRule::class);
+});
+
+test('not property access on arch expectations does not report undefined property', function (): void {
+    $this->analyse([
+        __DIR__.'/data/arch-expectation-not-property.php',
+    ], []);
+});
diff --git a/tests/Rules/data/arch-expectation-not-property.php b/tests/Rules/data/arch-expectation-not-property.php
new file mode 100644
index 0000000..802889e
--- /dev/null
+++ b/tests/Rules/data/arch-expectation-not-property.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+test('not property on arch expectation is allowed', function (): void {
+    expect('App')->toUseStrictTypes()->not->toUse(['dd', 'dump']);
+    expect('App')->toUseStrictTypes()->not->toBeFinal();
+    expect(['App\Models', 'App\Services'])->toUseStrictTypes()->not->toUse('Illuminate\Support\Facades\DB');
+});
diff --git a/tests/Type/data/arch-expectations.php b/tests/Type/data/arch-expectations.php
index 88b73dc..d7aae9e 100644
--- a/tests/Type/data/arch-expectations.php
+++ b/tests/Type/data/arch-expectations.php
@@ -109,3 +109,38 @@ function testToBeInvokable(): void
     $result = expect('App\Actions')->toBeInvokable();
     assertType(ArchExpectation::class, $result);
 }
+function testNotOnArchExpectation(): void
+{
+    $result = expect('App')->toUseStrictTypes()->not;
+    assertType("Pest\Expectations\OppositeExpectation<'App'>", $result);
+}
+
+function testNotArchExpectationChainToUse(): void
+{
+    $result = expect('App')->toUseStrictTypes()->not->toUse(['dd', 'dump']);
+    assertType(ArchExpectation::class, $result);
+}
+
+function testNotArchExpectationChainToBeFinal(): void
+{
+    $result = expect('App')->toUseStrictTypes()->not->toBeFinal();
+    assertType(ArchExpectation::class, $result);
+}
+
+function testNotArchExpectationChainToImplement(): void
+{
+    $result = expect('App')->toUseStrictTypes()->not->toImplement('SomeInterface');
+    assertType(ArchExpectation::class, $result);
+}
+
+function testNotOnExpectDirectly(): void
+{
+    $result = expect('App')->not->toUse(['dd', 'dump']);
+    assertType(ArchExpectation::class, $result);
+}
+
+function testNotOnArchExpectationArrayTarget(): void
+{
+    $result = expect(['App\Models', 'App\Services'])->toUseStrictTypes()->not;
+    assertType('Pest\Expectations\OppositeExpectation<array{\'App\\\\Models\', \'App\\\\Services\'}>', $result);
+}