diff --git a/spine-ts/core/src/Animation.ts b/spine-ts/core/src/Animation.ts
index c259e97b8..36ad09823 100644
--- a/spine-ts/core/src/Animation.ts
+++ b/spine-ts/core/src/Animation.ts
@@ -829,7 +829,7 @@ module spine {
 		}
 
 		setAttachment(skeleton: Skeleton, slot: Slot, attachmentName: string) {
-			slot.attachment = attachmentName == null ? null : skeleton.getAttachment(this.slotIndex, attachmentName);
+			slot.setAttachment(attachmentName == null ? null : skeleton.getAttachment(this.slotIndex, attachmentName));
 		}
 	}
 
diff --git a/spine-ts/core/src/AnimationState.ts b/spine-ts/core/src/AnimationState.ts
index ed648fffb..d509b90a4 100644
--- a/spine-ts/core/src/AnimationState.ts
+++ b/spine-ts/core/src/AnimationState.ts
@@ -260,7 +260,7 @@ module spine {
 				var slot = slots[i];
 				if (slot.attachmentState == setupState) {
 					var attachmentName = slot.data.attachmentName;
-					slot.attachment = (attachmentName == null ? null : skeleton.getAttachment(slot.data.index, attachmentName));
+					slot.setAttachment(attachmentName == null ? null : skeleton.getAttachment(slot.data.index, attachmentName));
 				}
 			}
 			this.unkeyedState += 2; // Increasing after each use avoids the need to reset attachmentState for every slot.