diff --git a/indra/llcommon/llinstancetracker.h b/indra/llcommon/llinstancetracker.h
index ecaf55586..3c096abe1 100644
--- a/indra/llcommon/llinstancetracker.h
+++ b/indra/llcommon/llinstancetracker.h
@@ -86,6 +86,7 @@ class LLInstanceTracker : public LLInstanceTrackerBase
 {
 	typedef LLInstanceTracker<T, KEY> MyT;
 	typedef typename std::map<KEY, T*> InstanceMap;
+	typedef typename InstanceMap::iterator::difference_type difference_type;
 	struct StaticData: public StaticBase
 	{
 		InstanceMap sMap;
@@ -115,6 +116,11 @@ public:
 		friend class boost::iterator_core_access;
 
 		void increment() { mIterator++; }
+		void decrement() { --mIterator; }
+		difference_type distance_to(instance_iter const& other) const
+		{
+			return std::distance(mIterator, other.mIterator);
+		}
 		bool equal(instance_iter const& other) const
 		{
 			return mIterator == other.mIterator;
@@ -155,6 +161,11 @@ public:
 		friend class boost::iterator_core_access;
 
 		void increment() { mIterator++; }
+		void decrement() { --mIterator; }
+		difference_type distance_to(instance_iter const& other) const
+		{
+			return std::distance(mIterator, other.mIterator);
+		}
 		bool equal(key_iter const& other) const
 		{
 			return mIterator == other.mIterator;