diff --git a/spine-cpp/spine-cpp/include/spine/AnimationState.h b/spine-cpp/spine-cpp/include/spine/AnimationState.h
index e4551f852..1145af569 100644
--- a/spine-cpp/spine-cpp/include/spine/AnimationState.h
+++ b/spine-cpp/spine-cpp/include/spine/AnimationState.h
@@ -393,7 +393,7 @@ namespace spine {
 		Vector<Event*> _events;
 		EventQueue* _queue;
 
-		Vector<int> _propertyIDs;
+		HashMap<int, bool> _propertyIDs;
 		bool _animationsChanged;
 
 		AnimationStateListener _listener;
diff --git a/spine-cpp/spine-cpp/include/spine/Extension.h b/spine-cpp/spine-cpp/include/spine/Extension.h
index c442ca98d..c9eb16f5e 100644
--- a/spine-cpp/spine-cpp/include/spine/Extension.h
+++ b/spine-cpp/spine-cpp/include/spine/Extension.h
@@ -30,6 +30,7 @@
 #ifndef Spine_Extension_h
 #define Spine_Extension_h
 
+
 #include <stdlib.h>
 #include <spine/dll.h>
 
diff --git a/spine-cpp/spine-cpp/include/spine/HashMap.h b/spine-cpp/spine-cpp/include/spine/HashMap.h
index 6ab4f0e1a..3ec2f5d24 100755
--- a/spine-cpp/spine-cpp/include/spine/HashMap.h
+++ b/spine-cpp/spine-cpp/include/spine/HashMap.h
@@ -89,11 +89,17 @@ public:
 	}
 
 	~HashMap() {
+		clear();
+	}
+
+	void clear() {
 		for (Entry *entry = _head; entry != NULL;) {
 			Entry* next = entry->next;
 			delete entry;
 			entry = next;
 		}
+		_head = NULL;
+		_size = 0;
 	}
 
 	size_t size() {
diff --git a/spine-cpp/spine-cpp/src/spine/AnimationState.cpp b/spine-cpp/spine-cpp/src/spine/AnimationState.cpp
index d5142a9d4..afa1dcab2 100644
--- a/spine-cpp/spine-cpp/src/spine/AnimationState.cpp
+++ b/spine-cpp/spine-cpp/src/spine/AnimationState.cpp
@@ -976,7 +976,7 @@ void AnimationState::computeHold(TrackEntry *entry) {
 	if (to != NULL && to->_holdPrevious) {
 		for (size_t i = 0; i < timelinesCount; i++) {
 			int id = timelines[i]->getPropertyId();
-			if (!_propertyIDs.contains(id)) _propertyIDs.add(id);
+			if (!_propertyIDs.containsKey(id)) _propertyIDs.put(id, true);
 			timelineMode[i] = Hold;
 		}
 		return;
@@ -988,10 +988,10 @@ void AnimationState::computeHold(TrackEntry *entry) {
 	for (; i < timelinesCount; ++i) {
 		Timeline *timeline = timelines[i];
 		int id = timeline->getPropertyId();
-		if (_propertyIDs.contains(id)) {
+		if (_propertyIDs.containsKey(id)) {
 			timelineMode[i] = Subsequent;
 		} else {
-			_propertyIDs.add(id);
+			_propertyIDs.put(id, true);
 
 			if (to == NULL || timeline->getRTTI().isExactly(AttachmentTimeline::rtti) ||
 					timeline->getRTTI().isExactly(DrawOrderTimeline::rtti) ||
@@ -1022,8 +1022,8 @@ void AnimationState::computeNotLast(TrackEntry *entry) {
 	for (size_t i = 0; i < timelinesCount; i++) {
 		if (timelines[i]->getRTTI().isExactly(AttachmentTimeline::rtti)) {
 			AttachmentTimeline *timeline = static_cast<AttachmentTimeline *>(timelines[i]);
-			if (!_propertyIDs.contains(timeline->getSlotIndex()))
-				_propertyIDs.add(timeline->getSlotIndex());
+			if (!_propertyIDs.containsKey(timeline->getSlotIndex()))
+				_propertyIDs.put(timeline->getSlotIndex(), true);
 			else
 				timelineMode[i] |= NotLast;
 		}