diff --git a/moses/FF/GlobalLexicalModel.cpp b/moses/FF/GlobalLexicalModel.cpp
index ef3fa4691..30cf4444d 100644
--- a/moses/FF/GlobalLexicalModel.cpp
+++ b/moses/FF/GlobalLexicalModel.cpp
@@ -43,7 +43,7 @@ GlobalLexicalModel::~GlobalLexicalModel()
   // delete words in the hash data structure
   DoubleHash::const_iterator iter;
   for(iter = m_hash.begin(); iter != m_hash.end(); iter++ ) {
-    map< const Word*, float, WordComparer >::const_iterator iter2;
+	boost::unordered_map< const Word*, float, WordComparer, WordComparer>::const_iterator iter2;
     for(iter2 = iter->second.begin(); iter2 != iter->second.end(); iter2++ ) {
       delete iter2->first; // delete input word
     }
diff --git a/moses/FF/GlobalLexicalModel.h b/moses/FF/GlobalLexicalModel.h
index 3d7f559d0..9889b1824 100644
--- a/moses/FF/GlobalLexicalModel.h
+++ b/moses/FF/GlobalLexicalModel.h
@@ -33,8 +33,8 @@ class InputType;
  */
 class GlobalLexicalModel : public StatelessFeatureFunction
 {
-  typedef std::map< const Word*, std::map< const Word*, float, WordComparer >, WordComparer > DoubleHash;
-  typedef std::map< const Word*, float, WordComparer > SingleHash;
+  typedef boost::unordered_map< const Word*, boost::unordered_map< const Word*, float, WordComparer, WordComparer >, WordComparer, WordComparer > DoubleHash;
+  typedef boost::unordered_map< const Word*, float, WordComparer, WordComparer > SingleHash;
   typedef std::map< const TargetPhrase*, float > LexiconCache;
 
   struct ThreadLocalStorage {
diff --git a/moses/GenerationDictionary.h b/moses/GenerationDictionary.h
index 67bbe1e91..33121315d 100644
--- a/moses/GenerationDictionary.h
+++ b/moses/GenerationDictionary.h
@@ -44,7 +44,7 @@ typedef std::map < Word , ScoreComponentCollection > OutputWordCollection;
  */
 class GenerationDictionary : public DecodeFeature
 {
-  typedef std::map<const Word* , OutputWordCollection, WordComparer> Collection;
+  typedef boost::unordered_map<const Word* , OutputWordCollection, WordComparer, WordComparer> Collection;
 protected:
   static std::vector<GenerationDictionary*> s_staticColl;
 
diff --git a/moses/Word.h b/moses/Word.h
index d82574573..d2b85296b 100644
--- a/moses/Word.h
+++ b/moses/Word.h
@@ -130,11 +130,6 @@ public:
     return !(*this == compare);
   }
 
-  int Compare(const Word &other) const {
-    return Compare(*this, other);
-  }
-
-
   /* static functions */
 
   /** transitive comparison of 2 word objects. Used by operator<.
@@ -159,10 +154,14 @@ public:
 };
 
 struct WordComparer {
-  //! returns true if hypoA can be recombined with hypoB
-  bool operator()(const Word *a, const Word *b) const {
-    return *a < *b;
+  size_t operator()(const Word* word) const {
+    return word->hash();
   }
+
+  bool operator()(const Word* a, const Word* b) const {
+    return (*a) == (*b);
+  }
+
 };