diff --git a/packages/database/src/Builder/ModelInspector.php b/packages/database/src/Builder/ModelInspector.php
index 89db10c89..3a24a044c 100644
--- a/packages/database/src/Builder/ModelInspector.php
+++ b/packages/database/src/Builder/ModelInspector.php
@@ -582,7 +582,7 @@ public function getSelectFields(): ImmutableArray
             }
         }
 
-        return $selectFields;
+        return $selectFields->unique();
     }
 
     public function resolveRelations(string $relationString, string $parent = '', array $visitedPaths = []): array
diff --git a/tests/Integration/Database/ModelInspector/ModelInspectorTest.php b/tests/Integration/Database/ModelInspector/ModelInspectorTest.php
index b6c38dd83..0c4bc894f 100644
--- a/tests/Integration/Database/ModelInspector/ModelInspectorTest.php
+++ b/tests/Integration/Database/ModelInspector/ModelInspectorTest.php
@@ -4,6 +4,7 @@
 
 use Tempest\Database\Casters\DataTransferObjectCaster;
 use Tempest\Database\IsDatabaseModel;
+use Tempest\Database\PrimaryKey;
 use Tempest\Database\Serializers\DataTransferObjectSerializer;
 use Tempest\Database\Virtual;
 use Tempest\Mapper\CastWith;
@@ -33,6 +34,35 @@ public function test_serialized_property_is_never_a_relation(): void
     {
         $this->assertFalse(inspect(ModelInspectorTestModelWithSerializedDtoProperty::class)->isRelation('dto'));
     }
+
+    public function test_select_doesnt_contain_duplicate_fields(): void
+    {
+        $model = inspect(HasRelatedModelWithId::class);
+
+        $selectedFields = $model->getSelectFields();
+
+        $this->assertEqualsCanonicalizing(
+            expected: ['name', 'relation_id'],
+            actual: $selectedFields->toArray(),
+        );
+    }
+}
+
+final class RelationWithId
+{
+    public PrimaryKey $id;
+
+    public string $name;
+}
+
+final class HasRelatedModelWithId
+{
+    public RelationWithId $relation;
+
+    public function __construct(
+        public string $name,
+        public int $relation_id,
+    ) {}
 }
 
 final class ModelInspectorTestDtoForModelWithVirtual