diff --git a/composer.json b/composer.json
index d1f7404..1bf4ffc 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,9 @@
         "phpstan/phpstan-deprecation-rules": "^1.2.1",
         "phpstan/phpstan-symfony": "^1.4.14",
         "phpunit/phpunit": "^11.5.15",
-        "thecodingmachine/safe": "^2 || ^3.0"
+        "thecodingmachine/safe": "^2 || ^3.0",
+        "mockery/mockery": "^1.6",
+        "phpstan/phpstan-mockery": "^1.1"
     },
     "config": {
         "allow-plugins": {
diff --git a/src/Library/LibraryBuilder.php b/src/Library/LibraryBuilder.php
index 0509f0b..1476a57 100644
--- a/src/Library/LibraryBuilder.php
+++ b/src/Library/LibraryBuilder.php
@@ -61,6 +61,9 @@ public static function solveDeps(ResourceInterface $resource, PintoMapping $pint
             }
         }
 
+        // Regular is good for objects.
+        $deps = \array_unique($deps, \SORT_REGULAR);
+
         if ([] === $deps) {
             return DependencyCollection::create([]);
         }
diff --git a/tests/PintoDependenciesTest.php b/tests/PintoDependenciesTest.php
index 31ed5a4..34c8832 100644
--- a/tests/PintoDependenciesTest.php
+++ b/tests/PintoDependenciesTest.php
@@ -11,9 +11,11 @@
 use Pinto\Library\DependencyCollection;
 use Pinto\Library\LibraryBuilder;
 use Pinto\List\Resource\ObjectListEnumResource;
+use Pinto\Resource\ResourceInterface;
 use Pinto\tests\fixtures\Lists\DependencyOn\PintoListDependencies;
 use Pinto\tests\fixtures\Lists\DependencyOn\PintoListDependenciesHierarchyChild;
 use Pinto\tests\fixtures\Lists\DependencyOn\PintoListDependenciesHierarchyParent;
+use Pinto\tests\fixtures\Lists\PintoList;
 use Pinto\tests\fixtures\Objects\DependencyOn\PintoObjectDependencyOnChild;
 use Pinto\tests\fixtures\Objects\DependencyOn\PintoObjectDependencyOnParent;
 
@@ -102,4 +104,28 @@ public function testDependencyOnParent(): void
             ObjectListEnumResource::createFromEnum(PintoListDependenciesHierarchyParent::Parent),
         ]), LibraryBuilder::solveDeps(PintoListDependenciesHierarchyChild::Child, $pintoMapping));
     }
+
+    public function testDeduplicateDependencies(): void
+    {
+        $objectListEnum = PintoList::Pinto_Object;
+        $resource = \Mockery::mock(ResourceInterface::class);
+        $resource->expects('dependencies')->andReturn([
+            new DependencyOn(dependency: $objectListEnum),
+            new DependencyOn(dependency: $objectListEnum),
+        ]);
+        $pintoMapping = new \Pinto\PintoMapping(
+            resources: [
+                'untestedKey' => ObjectListEnumResource::createFromEnum($objectListEnum),
+            ],
+            definitions: [],
+            buildInvokers: [],
+            types: [],
+            lsbFactoryCanonicalObjectClasses: [],
+        );
+
+        $dependencyCollection = LibraryBuilder::solveDeps($resource, $pintoMapping);
+        static::assertEquals([
+            ObjectListEnumResource::createFromEnum($objectListEnum),
+        ], \iterator_to_array($dependencyCollection));
+    }
 }