diff --git a/src/Container/GenericContainer.php b/src/Container/GenericContainer.php
index d44eb35..8031963 100644
--- a/src/Container/GenericContainer.php
+++ b/src/Container/GenericContainer.php
@@ -120,8 +120,8 @@ public function addInitializer(ReflectionClass|string $initializerClass): Contai
         $initializeMethod = $initializerClass->getMethod('initialize');
 
         // We resolve the optional Tag attribute from this initializer class
-        $tag = Attributes::find(Tag::class)->in($initializerClass)->first()
-            ?? Attributes::find(Tag::class)->in($initializeMethod)->first();
+        $singleton = Attributes::find(Singleton::class)->in($initializerClass)->first()
+            ?? Attributes::find(Singleton::class)->in($initializeMethod)->first();
 
         // For normal Initializers, we'll use the return type
         // to determine which dependency they resolve
@@ -134,7 +134,7 @@ public function addInitializer(ReflectionClass|string $initializerClass): Contai
 
         /** @var ReflectionNamedType[] $returnTypes */
         foreach ($returnTypes as $returnType) {
-            $this->initializers[$this->resolveTaggedName($returnType->getName(), $tag?->name)] = $initializerClass->getName();
+            $this->initializers[$this->resolveTaggedName($returnType->getName(), $singleton?->tag)] = $initializerClass->getName();
         }
 
         return $this;
diff --git a/src/Container/Singleton.php b/src/Container/Singleton.php
index fa96ec3..83da622 100644
--- a/src/Container/Singleton.php
+++ b/src/Container/Singleton.php
@@ -9,4 +9,8 @@
 #[Attribute]
 final readonly class Singleton
 {
+    public function __construct(
+        public ?string $tag = null,
+    ) {
+    }
 }
diff --git a/tests/Unit/Container/Fixtures/TaggedDependencyCliInitializer.php b/tests/Unit/Container/Fixtures/TaggedDependencyCliInitializer.php
index 572e74d..eed449b 100644
--- a/tests/Unit/Container/Fixtures/TaggedDependencyCliInitializer.php
+++ b/tests/Unit/Container/Fixtures/TaggedDependencyCliInitializer.php
@@ -6,9 +6,9 @@
 
 use Tempest\Container\Container;
 use Tempest\Container\Initializer;
-use Tempest\Container\Tag;
+use Tempest\Container\Singleton;
 
-#[Tag('cli')]
+#[Singleton('cli')]
 final readonly class TaggedDependencyCliInitializer implements Initializer
 {
     public function initialize(Container $container): TaggedDependency
diff --git a/tests/Unit/Container/Fixtures/TaggedDependencyWebInitializer.php b/tests/Unit/Container/Fixtures/TaggedDependencyWebInitializer.php
index db3ee7a..7dc7aec 100644
--- a/tests/Unit/Container/Fixtures/TaggedDependencyWebInitializer.php
+++ b/tests/Unit/Container/Fixtures/TaggedDependencyWebInitializer.php
@@ -6,9 +6,9 @@
 
 use Tempest\Container\Container;
 use Tempest\Container\Initializer;
-use Tempest\Container\Tag;
+use Tempest\Container\Singleton;
 
-#[Tag('web')]
+#[Singleton('web')]
 final readonly class TaggedDependencyWebInitializer implements Initializer
 {
     public function initialize(Container $container): TaggedDependency