diff --git a/src/ServiceManager.php b/src/ServiceManager.php
index 466702a8..ada28605 100644
--- a/src/ServiceManager.php
+++ b/src/ServiceManager.php
@@ -705,8 +705,7 @@ private function mergeDelegators(array $config): array
     {
         foreach ($config as $key => $delegators) {
             if (! array_key_exists($key, $this->delegators)) {
-                $this->delegators[$key] = $delegators;
-                continue;
+                $this->delegators[$key] = [];
             }
 
             foreach ($delegators as $delegator) {
diff --git a/test/ServiceManagerTest.php b/test/ServiceManagerTest.php
index 06fb2ad3..3fd452e7 100644
--- a/test/ServiceManagerTest.php
+++ b/test/ServiceManagerTest.php
@@ -5,6 +5,7 @@
 namespace LaminasTest\ServiceManager;
 
 use DateTime;
+use Laminas\ContainerConfigTest\TestAsset\DelegatorFactory;
 use Laminas\ServiceManager\Factory\AbstractFactoryInterface;
 use Laminas\ServiceManager\Factory\FactoryInterface;
 use Laminas\ServiceManager\Factory\InvokableFactory;
@@ -372,6 +373,30 @@ public function testFactoryMayBeStaticMethodDescribedByCallableString(): void
         self::assertEquals(stdClass::class, $serviceManager->get(stdClass::class)::class);
     }
 
+    public function testDuplicateDelegatorsAreRemoved(): void
+    {
+        $dependencies   = [
+            'delegators' => [
+                DateTime::class => [
+                    DelegatorFactory::class,
+                    DelegatorFactory::class,
+                ],
+            ],
+        ];
+        $serviceManager = new ServiceManager($dependencies);
+        $property       = new ReflectionProperty(ServiceManager::class, "delegators");
+        $property->setAccessible(true);
+        $delegators = $property->getValue($serviceManager);
+        self::assertSame(
+            [
+                DateTime::class => [
+                    DelegatorFactory::class,
+                ],
+            ],
+            $delegators
+        );
+    }
+
     public function testResolvedAliasFromAbstractFactory(): void
     {
         $abstractFactory = $this->createMock(AbstractFactoryInterface::class);