diff --git a/contrib/other-builds/moses2/Search/CubePruning/Misc.h b/contrib/other-builds/moses2/Search/CubePruning/Misc.h
index 58a8343f0..6727f5b33 100644
--- a/contrib/other-builds/moses2/Search/CubePruning/Misc.h
+++ b/contrib/other-builds/moses2/Search/CubePruning/Misc.h
@@ -60,7 +60,11 @@ public:
 	typedef std::priority_queue<QueueItem*,
 				std::vector<QueueItem*>,
 				QueueItemOrderer> Queue;
-	typedef boost::unordered_set< std::pair<const CubeEdge*, int> > SeenPositions;
+	typedef boost::unordered_set< std::pair<const CubeEdge*, int>,
+			  boost::hash< std::pair<const CubeEdge*, int> >,
+			  std::equal_to< std::pair<const CubeEdge*, int> >,
+			  MemPoolAllocator< std::pair<const CubeEdge*, int> >
+			  > SeenPositions;
 
 	const Hypotheses &hypos;
 	const InputPath &path;
diff --git a/contrib/other-builds/moses2/Search/CubePruning/Search.cpp b/contrib/other-builds/moses2/Search/CubePruning/Search.cpp
index 35f77e6e1..4c62a2c3b 100644
--- a/contrib/other-builds/moses2/Search/CubePruning/Search.cpp
+++ b/contrib/other-builds/moses2/Search/CubePruning/Search.cpp
@@ -28,7 +28,7 @@ Search::Search(Manager &mgr)
 :Moses2::Search(mgr)
 ,m_stacks(mgr)
 ,m_queue(mgr.system.GetQueue())
-,m_seenPositions(mgr.system.GetSeenPositions())
+,m_seenPositions(MemPoolAllocator<std::pair<const CubeEdge*, int>>(mgr.GetPool()))
 {
 }
 
diff --git a/contrib/other-builds/moses2/Search/CubePruning/Search.h b/contrib/other-builds/moses2/Search/CubePruning/Search.h
index 05e75732d..106f28f44 100644
--- a/contrib/other-builds/moses2/Search/CubePruning/Search.h
+++ b/contrib/other-builds/moses2/Search/CubePruning/Search.h
@@ -35,7 +35,7 @@ public:
 protected:
 	NSCubePruning::Stacks m_stacks;
 	NSCubePruning::CubeEdge::Queue &m_queue;
-	NSCubePruning::CubeEdge::SeenPositions &m_seenPositions;
+	NSCubePruning::CubeEdge::SeenPositions m_seenPositions;
 
 	// CUBE PRUNING VARIABLES
 	// setup
diff --git a/contrib/other-builds/moses2/System.cpp b/contrib/other-builds/moses2/System.cpp
index e7aa53067..0b1e363a8 100644
--- a/contrib/other-builds/moses2/System.cpp
+++ b/contrib/other-builds/moses2/System.cpp
@@ -170,10 +170,5 @@ NSCubePruning::CubeEdge::Queue &System::GetQueue() const
   return GetThreadSpecificObj(m_queue);
 }
 
-NSCubePruning::CubeEdge::SeenPositions &System::GetSeenPositions() const
-{
-  return GetThreadSpecificObj(m_seenPositions);
-}
-
 }
 
diff --git a/contrib/other-builds/moses2/System.h b/contrib/other-builds/moses2/System.h
index 1ef2b999a..3917ece18 100644
--- a/contrib/other-builds/moses2/System.h
+++ b/contrib/other-builds/moses2/System.h
@@ -66,7 +66,6 @@ public:
 	ObjectPoolContiguous<Hypothesis*> &GetBatchForEval() const;
 	Bitmaps &GetBitmaps() const;
 	NSCubePruning::CubeEdge::Queue &GetQueue() const;
-	NSCubePruning::CubeEdge::SeenPositions &GetSeenPositions() const;
 
 protected:
   mutable FactorCollection m_vocab;
@@ -75,7 +74,6 @@ protected:
   mutable boost::thread_specific_ptr< ObjectPoolContiguous<Hypothesis*> > m_batchForEval;
 
   mutable boost::thread_specific_ptr< NSCubePruning::CubeEdge::Queue> m_queue;
-  mutable boost::thread_specific_ptr< NSCubePruning::CubeEdge::SeenPositions> m_seenPositions;
 
   mutable boost::thread_specific_ptr<Bitmaps> m_bitmaps;