diff --git a/src/EcsAspect.cs b/src/EcsAspect.cs
index dc11329..5d5aa29 100644
--- a/src/EcsAspect.cs
+++ b/src/EcsAspect.cs
@@ -5,7 +5,7 @@ using System.Collections.Generic;
 
 namespace DCFApixels.DragonECS
 {
-    public abstract class EcsAspect : ITemplateNode
+    public abstract class EcsAspect : ITemplateNode, IEcsComponentMask
     {
         #region Initialization Halpers
         [ThreadStatic]
@@ -302,6 +302,10 @@ namespace DCFApixels.DragonECS
             }
         }
         #endregion
+
+        #region Other
+        EcsMask IEcsComponentMask.ToMask(EcsWorld world) { return _mask; }
+        #endregion
     }
 
     #region EcsAspectExtensions
diff --git a/src/EcsMask.cs b/src/EcsMask.cs
index 4863815..8d135dc 100644
--- a/src/EcsMask.cs
+++ b/src/EcsMask.cs
@@ -495,10 +495,26 @@ namespace DCFApixels.DragonECS
         {
             return a.World.Get<WorldMaskComponent>().ExceptMask(a, b);
         }
+        public static EcsMask operator -(EcsMask a, IEcsComponentMask b)
+        {
+            return a.World.Get<WorldMaskComponent>().ExceptMask(a, b.ToMask(a.World));
+        }
+        public static EcsMask operator -(IEcsComponentMask b, EcsMask a)
+        {
+            return a.World.Get<WorldMaskComponent>().ExceptMask(b.ToMask(a.World), a);
+        }
         public static EcsMask operator +(EcsMask a, EcsMask b)
         {
             return a.World.Get<WorldMaskComponent>().CombineMask(a, b);
         }
+        public static EcsMask operator +(EcsMask a, IEcsComponentMask b)
+        {
+            return a.World.Get<WorldMaskComponent>().CombineMask(a, b.ToMask(a.World));
+        }
+        public static EcsMask operator +(IEcsComponentMask b, EcsMask a)
+        {
+            return a.World.Get<WorldMaskComponent>().CombineMask(b.ToMask(a.World), a);
+        }
         public static implicit operator EcsMask((IEcsComponentMask mask, EcsWorld world) a)
         {
             return a.mask.ToMask(a.world);
diff --git a/src/Executors/Queries.cs b/src/Executors/Queries.cs
index bce01fb..3e028c2 100644
--- a/src/Executors/Queries.cs
+++ b/src/Executors/Queries.cs
@@ -15,7 +15,7 @@ namespace DCFApixels.DragonECS
             where TAspect : EcsAspect, new()
             where TCollection : IEntityStorage
         {
-            if(ReferenceEquals(entities, entities.World))
+            if (ReferenceEquals(entities, entities.World))
             {
                 entities.World.GetQueryCache(out EcsWhereExecutor executor, out aspect);
                 return executor.Execute();