diff --git a/src/Spine.ts b/src/Spine.ts
index 854f08d..8ccc032 100644
--- a/src/Spine.ts
+++ b/src/Spine.ts
@@ -125,7 +125,8 @@ export class Spine extends Container implements View
     public skeletonBounds: SkeletonBounds;
     private _debug?: ISpineDebugRenderer | undefined = undefined;
 
-    readonly _slotsObject: { slot: Slot; container: Container }[] = [];
+    readonly _slotsObject: Record<string, {slot:Slot, container:Container}> = Object.create(null);
+
     private getSlotFromRef(slotRef: number | string | Slot): Slot
     {
         let slot: Slot | null;
@@ -503,10 +504,12 @@ export class Spine extends Container implements View
      */
     private updateSlotAttachments()
     {
-        for (let i = 0; i < this._slotsObject.length; i++)
+        for (const i in this._slotsObject)
         {
             const slotAttachment = this._slotsObject[i];
 
+            if (!slotAttachment) continue;
+
             const { slot, container } = slotAttachment;
 
             container.visible = this.skeleton.drawOrder.includes(slot);
@@ -599,22 +602,38 @@ export class Spine extends Container implements View
      * @param container - The container to attach to the slot
      * @param slotRef - The slot id or  slot to attach to
      */
-    addSlotObject(slotRef: number | string | Slot, container: Container)
+    addSlotObject(slot: number | string | Slot, container: Container)
     {
-        this.removeSlotObject(slotRef, container);
+        slot = this.getSlotFromRef(slot);
 
-        container.includeInBuild = false;
+        // need to check in on the container too...
+        for (const i in this._slotsObject)
+        {
+            if (this._slotsObject[i]?.container === container)
+            {
+                this.removeSlotObject(this._slotsObject[i].slot);
+            }
+        }
 
-        slotRef = this.getSlotFromRef(slotRef);
+        this.removeSlotObject(slot);
+
+        container.includeInBuild = false;
 
         // TODO only add once??
         this.addChild(container);
 
         // TODO search for copies... - one container - to one bone!
-        this._slotsObject.push({
-            slot: slotRef,
+        this._slotsObject[slot.data.name] = {
             container,
-        });
+            slot
+        };
+
+        const renderGroup = this.renderGroup || this.parentRenderGroup;
+
+        if (renderGroup)
+        {
+            renderGroup.structureDidChange = true;
+        }
     }
 
     /**
@@ -623,24 +642,20 @@ export class Spine extends Container implements View
      * @param container - The container to detach from the slot
      * @param slot - The slot id or slot to detach from
      */
-    removeSlotObject(slot: number | string | Slot, container: Container)
+    removeSlotObject(slot: number | string | Slot)
     {
-        container.includeInBuild = true;
-
         slot = this.getSlotFromRef(slot);
 
-        this.removeChild(container);
+        const container = this._slotsObject[slot.data.name]?.container;
 
-        for (let i = 0; i < this._slotsObject.length; i++)
+        if (container)
         {
-            const mapping = this._slotsObject[i];
+            this.removeChild(container);
 
-            if (mapping.slot === slot && mapping.container === container)
-            {
-                this._slotsObject.splice(i, 1);
-                break;
-            }
+            container.includeInBuild = true;
         }
+
+        this._slotsObject[slot.data.name] = null;
     }
 
     /**
@@ -649,11 +664,11 @@ export class Spine extends Container implements View
      * @param slotRef - The slot id or slot to get the attachment from
      * @returns - The container attached to the slot
      */
-    getSlotObject(slotRef: number | string | Slot)
+    getSlotObject(slot: number | string | Slot)
     {
-        slotRef = this.getSlotFromRef(slotRef);
+        slot = this.getSlotFromRef(slot);
 
-        return this._slotsObject.find((mapping) => mapping.slot === slotRef)?.container;
+        return this._slotsObject[slot.data.name].container;
     }
 
     updateBounds()
diff --git a/src/SpinePipe.ts b/src/SpinePipe.ts
index f466ae6..28275e9 100644
--- a/src/SpinePipe.ts
+++ b/src/SpinePipe.ts
@@ -115,7 +115,7 @@ export class SpinePipe implements RenderPipe<Spine>
                 }
             }
 
-            const containerAttachment = spine._slotsObject.find((mapping) => mapping.slot === slot);
+            const containerAttachment = spine._slotsObject[slot.data.name];
 
             if (containerAttachment)
             {