diff --git a/src/Pools/EcsPoolBase.cs b/src/Pools/EcsPoolBase.cs
index bdb9902..c8f54af 100644
--- a/src/Pools/EcsPoolBase.cs
+++ b/src/Pools/EcsPoolBase.cs
@@ -1,6 +1,7 @@
 using DCFApixels.DragonECS.Internal;
 using DCFApixels.DragonECS.PoolsCore;
 using System;
+using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 
 namespace DCFApixels.DragonECS.PoolsCore