diff --git a/spine-cpp/spine-cpp/include/spine/Animation.h b/spine-cpp/spine-cpp/include/spine/Animation.h
index a670c3bca..311a02989 100644
--- a/spine-cpp/spine-cpp/include/spine/Animation.h
+++ b/spine-cpp/spine-cpp/include/spine/Animation.h
@@ -110,7 +110,7 @@ namespace spine {
 
 		Vector<Timeline *> &getTimelines();
 
-		bool hasTimeline(Vector<PropertyId> ids);
+		bool hasTimeline(Vector<PropertyId> &ids);
 
 		float getDuration();
 
diff --git a/spine-cpp/spine-cpp/src/spine/Animation.cpp b/spine-cpp/spine-cpp/src/spine/Animation.cpp
index bd5545ed4..f5ab306ad 100644
--- a/spine-cpp/spine-cpp/src/spine/Animation.cpp
+++ b/spine-cpp/spine-cpp/src/spine/Animation.cpp
@@ -50,7 +50,7 @@ Animation::Animation(const String &name, Vector<Timeline *> &timelines, float du
 	}
 }
 
-bool Animation::hasTimeline(Vector<PropertyId> ids) {
+bool Animation::hasTimeline(Vector<PropertyId> &ids) {
 	for (size_t i = 0; i < ids.size(); i++) {
 		if (_timelineIds.containsKey(ids[i])) return true;
 	}