diff --git a/src/Analyzer/ClassDescription.php b/src/Analyzer/ClassDescription.php
index 93545a98..9e8d7899 100644
--- a/src/Analyzer/ClassDescription.php
+++ b/src/Analyzer/ClassDescription.php
@@ -103,6 +103,11 @@ public function namespaceMatches(string $pattern): bool
         return $this->FQCN->matches($pattern);
     }
 
+    public function namespaceMatchesExactly(string $namespace): bool
+    {
+        return $this->FQCN->namespace() === $namespace;
+    }
+
     public function namespaceMatchesOneOfTheseNamespaces(array $classesToBeExcluded): bool
     {
         foreach ($classesToBeExcluded as $classToBeExcluded) {
diff --git a/src/Expression/ForClasses/NotResideInOneOfTheseNamespacesExactly.php b/src/Expression/ForClasses/NotResideInOneOfTheseNamespacesExactly.php
new file mode 100644
index 00000000..a35524c2
--- /dev/null
+++ b/src/Expression/ForClasses/NotResideInOneOfTheseNamespacesExactly.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Arkitect\Expression\ForClasses;
+
+use Arkitect\Analyzer\ClassDescription;
+use Arkitect\Expression\Description;
+use Arkitect\Expression\Expression;
+use Arkitect\Rules\Violation;
+use Arkitect\Rules\ViolationMessage;
+use Arkitect\Rules\Violations;
+
+class NotResideInOneOfTheseNamespacesExactly implements Expression
+{
+    /** @var array<string> */
+    private $namespaces;
+
+    public function __construct(string ...$namespaces)
+    {
+        $this->namespaces = $namespaces;
+    }
+
+    public function describe(ClassDescription $theClass, string $because): Description
+    {
+        $descr = implode(', ', $this->namespaces);
+
+        return new Description("should not reside in one of these namespaces exactly: $descr", $because);
+    }
+
+    public function evaluate(ClassDescription $theClass, Violations $violations, string $because): void
+    {
+        $resideInNamespace = false;
+        foreach ($this->namespaces as $namespace) {
+            if ($theClass->namespaceMatchesExactly($namespace)) {
+                $resideInNamespace = true;
+            }
+        }
+
+        if ($resideInNamespace) {
+            $violation = Violation::create(
+                $theClass->getFQCN(),
+                ViolationMessage::selfExplanatory($this->describe($theClass, $because)),
+                $theClass->getFilePath()
+            );
+            $violations->add($violation);
+        }
+    }
+}
diff --git a/src/Expression/ForClasses/ResideInOneOfTheseNamespacesExactly.php b/src/Expression/ForClasses/ResideInOneOfTheseNamespacesExactly.php
new file mode 100644
index 00000000..92e498e3
--- /dev/null
+++ b/src/Expression/ForClasses/ResideInOneOfTheseNamespacesExactly.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Arkitect\Expression\ForClasses;
+
+use Arkitect\Analyzer\ClassDescription;
+use Arkitect\Expression\Description;
+use Arkitect\Expression\Expression;
+use Arkitect\Rules\Violation;
+use Arkitect\Rules\ViolationMessage;
+use Arkitect\Rules\Violations;
+
+class ResideInOneOfTheseNamespacesExactly implements Expression
+{
+    /** @var array<string> */
+    private $namespaces;
+
+    public function __construct(string ...$namespaces)
+    {
+        $this->namespaces = array_values(array_unique($namespaces));
+    }
+
+    public function describe(ClassDescription $theClass, string $because): Description
+    {
+        $descr = implode(', ', $this->namespaces);
+
+        return new Description("should reside in one of these namespaces exactly: $descr", $because);
+    }
+
+    public function evaluate(ClassDescription $theClass, Violations $violations, string $because): void
+    {
+        $resideInNamespace = false;
+        foreach ($this->namespaces as $namespace) {
+            if ($theClass->namespaceMatchesExactly($namespace)) {
+                $resideInNamespace = true;
+            }
+        }
+
+        if (!$resideInNamespace) {
+            $violation = Violation::create(
+                $theClass->getFQCN(),
+                ViolationMessage::selfExplanatory($this->describe($theClass, $because)),
+                $theClass->getFilePath()
+            );
+            $violations->add($violation);
+        }
+    }
+}
diff --git a/tests/Unit/Expressions/ForClasses/NotResideInOneOfTheseNamespacesExactlyTest.php b/tests/Unit/Expressions/ForClasses/NotResideInOneOfTheseNamespacesExactlyTest.php
new file mode 100644
index 00000000..d20dfc89
--- /dev/null
+++ b/tests/Unit/Expressions/ForClasses/NotResideInOneOfTheseNamespacesExactlyTest.php
@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Arkitect\Tests\Unit\Expressions\ForClasses;
+
+use Arkitect\Analyzer\ClassDescription;
+use Arkitect\Expression\ForClasses\NotResideInOneOfTheseNamespacesExactly;
+use Arkitect\Rules\Violations;
+use PHPUnit\Framework\TestCase;
+
+class NotResideInOneOfTheseNamespacesExactlyTest extends TestCase
+{
+    public function test_it_should_return_true_if_not_reside_in_namespace(): void
+    {
+        $haveNameMatching = new NotResideInOneOfTheseNamespacesExactly('MyNamespace');
+
+        $classDesc = ClassDescription::getBuilder('AnotherNamespace\HappyIsland', 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertEquals(0, $violations->count());
+    }
+
+    public function test_it_should_return_true_if_reside_in_child_namespace(): void
+    {
+        $haveNameMatching = new NotResideInOneOfTheseNamespacesExactly('MyNamespace');
+
+        $classDesc = ClassDescription::getBuilder('MyNamespace\Child\HappyIsland', 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertEquals(0, $violations->count(), 'should not violate when in child namespace');
+    }
+
+    public function test_it_should_return_false_if_reside_in_exact_namespace(): void
+    {
+        $namespace = 'MyNamespace';
+        $haveNameMatching = new NotResideInOneOfTheseNamespacesExactly($namespace);
+
+        $classDesc = ClassDescription::getBuilder('MyNamespace\HappyIsland', 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertEquals(1, $violations->count());
+        self::assertEquals(
+            'should not reside in one of these namespaces exactly: '.$namespace.' because we want to add this rule for our software',
+            $haveNameMatching->describe($classDesc, $because)->toString()
+        );
+    }
+
+    public function test_it_should_check_multiple_namespaces_in_or(): void
+    {
+        $haveNameMatching = new NotResideInOneOfTheseNamespacesExactly('AnotherNamespace', 'ASecondNamespace', 'AThirdNamespace');
+
+        $classDesc = ClassDescription::getBuilder('AnotherNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $because = 'we want to add this rule for our software';
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(1, $violations->count());
+
+        $classDesc = ClassDescription::getBuilder('MyNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(0, $violations->count());
+
+        $classDesc = ClassDescription::getBuilder('AThirdNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(1, $violations->count());
+    }
+}
diff --git a/tests/Unit/Expressions/ForClasses/ResideInOneOfTheseNamespacesExactlyTest.php b/tests/Unit/Expressions/ForClasses/ResideInOneOfTheseNamespacesExactlyTest.php
new file mode 100644
index 00000000..f324cd84
--- /dev/null
+++ b/tests/Unit/Expressions/ForClasses/ResideInOneOfTheseNamespacesExactlyTest.php
@@ -0,0 +1,118 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Arkitect\Tests\Unit\Expressions\ForClasses;
+
+use Arkitect\Analyzer\ClassDescription;
+use Arkitect\Expression\ForClasses\ResideInOneOfTheseNamespacesExactly;
+use Arkitect\Rules\Violations;
+use PHPUnit\Framework\TestCase;
+
+class ResideInOneOfTheseNamespacesExactlyTest extends TestCase
+{
+    public static function shouldMatchNamespacesProvider(): array
+    {
+        return [
+            ['Food\Vegetables', 'Food\Vegetables\Carrot', 'matches a class in the exact namespace'],
+            ['Food', 'Food\Vegetables', 'matches a class in the exact namespace'],
+            ['', 'Carrot', 'matches a class in the root namespace'],
+        ];
+    }
+
+    /**
+     * @dataProvider shouldMatchNamespacesProvider
+     *
+     * @param mixed $expectedNamespace
+     * @param mixed $actualFQCN
+     * @param mixed $explanation
+     */
+    public function test_it_should_match_exact_namespace($expectedNamespace, $actualFQCN, $explanation): void
+    {
+        $haveNameMatching = new ResideInOneOfTheseNamespacesExactly($expectedNamespace);
+
+        $classDesc = ClassDescription::getBuilder($actualFQCN, 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertEquals(0, $violations->count(), $explanation);
+    }
+
+    public static function shouldNotMatchNamespacesProvider(): array
+    {
+        return [
+            ['Food\Vegetables', 'Food\Vegetables\Roots\Carrot', 'should not match a class in a child namespace'],
+            ['Food\Vegetables', 'Food\Vegetables\Roots\Orange\Carrot', 'should not match a class in a child of a child namespace'],
+            ['Food', 'Food\Vegetables\Carrot', 'should not match a class in a child namespace'],
+            ['Food\Vegetables\Roots', 'Food\Vegetables\Carrot', 'should not match a class in a different namespace'],
+        ];
+    }
+
+    /**
+     * @dataProvider shouldNotMatchNamespacesProvider
+     *
+     * @param mixed $expectedNamespace
+     * @param mixed $actualFQCN
+     * @param mixed $explanation
+     */
+    public function test_it_should_not_match_child_namespaces($expectedNamespace, $actualFQCN, $explanation): void
+    {
+        $haveNameMatching = new ResideInOneOfTheseNamespacesExactly($expectedNamespace);
+
+        $classDesc = ClassDescription::getBuilder($actualFQCN, 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertNotEquals(0, $violations->count(), $explanation);
+    }
+
+    public function test_it_should_return_false_if_not_reside_in_namespace(): void
+    {
+        $haveNameMatching = new ResideInOneOfTheseNamespacesExactly('MyNamespace');
+
+        $classDesc = ClassDescription::getBuilder('AnotherNamespace\HappyIsland', 'src/Foo.php')->build();
+        $because = 'we want to add this rule for our software';
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+
+        self::assertNotEquals(0, $violations->count());
+    }
+
+    public function test_it_should_check_multiple_namespaces_in_or(): void
+    {
+        $haveNameMatching = new ResideInOneOfTheseNamespacesExactly('MyNamespace', 'AnotherNamespace', 'AThirdNamespace');
+
+        $classDesc = ClassDescription::getBuilder('AnotherNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $because = 'we want to add this rule for our software';
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(0, $violations->count());
+
+        $classDesc = ClassDescription::getBuilder('MyNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(0, $violations->count());
+
+        $classDesc = ClassDescription::getBuilder('AThirdNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertEquals(0, $violations->count());
+
+        $classDesc = ClassDescription::getBuilder('NopeNamespace\HappyIsland', 'src/Foo.php')->build();
+        $violations = new Violations();
+        $haveNameMatching->evaluate($classDesc, $violations, $because);
+        self::assertNotEquals(0, $violations->count());
+    }
+
+    public function test_duplicate_namespaces_are_removed(): void
+    {
+        $expression = new ResideInOneOfTheseNamespacesExactly('A', 'B', 'A', 'C', 'D', 'D');
+
+        self::assertSame(
+            'should reside in one of these namespaces exactly: A, B, C, D because rave',
+            $expression->describe(ClassDescription::getBuilder('Marko', 'src/Foo.php')->build(), 'rave')->toString()
+        );
+    }
+}