diff --git a/indra/newview/llvoavatar.h b/indra/newview/llvoavatar.h
index f4f1235d55ea74d494c5fc80061b701a972029e5..a779a1735c6f6fb952de98b69a238debbef64224 100644
--- a/indra/newview/llvoavatar.h
+++ b/indra/newview/llvoavatar.h
@@ -33,6 +33,8 @@
 #include <string>
 #include <vector>
 
+#include <boost/signals2.hpp>
+
 #include "imageids.h"			// IMG_INVISIBLE
 #include "llchat.h"
 #include "lldrawpoolalpha.h"
@@ -71,7 +73,8 @@ class LLVOAvatarSkeletonInfo;
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 class LLVOAvatar :
 	public LLViewerObject,
-	public LLCharacter
+	public LLCharacter,
+	public boost::signals2::trackable
 {
 public:
 	friend class LLVOAvatarSelf;