diff --git a/src/DictTrie.hpp b/src/DictTrie.hpp
index 15de328..f5347b5 100644
--- a/src/DictTrie.hpp
+++ b/src/DictTrie.hpp
@@ -71,7 +71,7 @@ class DictTrie {
     vector<Dag>& res) const {
     trie_->find(begin, end, res);
   }
-  bool isUserDictSingleChineseWord(const Unicode::value_type& word) const {
+  bool isUserDictSingleChineseWord(const Rune& word) const {
     return isIn(userDictSingleChineseWord_, word);
   }
   double getMinWeight() const {
@@ -198,7 +198,7 @@ class DictTrie {
 
   double minWeight_;
   double maxWeight_;
-  unordered_set<Unicode::value_type> userDictSingleChineseWord_;
+  unordered_set<Rune> userDictSingleChineseWord_;
 };
 }
 
diff --git a/src/HMMSegment.hpp b/src/HMMSegment.hpp
index 46aa8d9..83769b2 100644
--- a/src/HMMSegment.hpp
+++ b/src/HMMSegment.hpp
@@ -74,7 +74,7 @@ class HMMSegment: public SegmentBase {
  private:
   // sequential letters rule
   Unicode::const_iterator sequentialLetterRule_(Unicode::const_iterator begin, Unicode::const_iterator end) const {
-    Unicode::value_type x = *begin;
+    Rune x = *begin;
     if (('a' <= x && x <= 'z') || ('A' <= x && x <= 'Z')) {
       begin ++;
     } else {
@@ -92,7 +92,7 @@ class HMMSegment: public SegmentBase {
   }
   //
   Unicode::const_iterator numbersRule_(Unicode::const_iterator begin, Unicode::const_iterator end) const {
-    Unicode::value_type x = *begin;
+    Rune x = *begin;
     if('0' <= x && x <= '9') {
       begin ++;
     } else {
diff --git a/src/MPSegment.hpp b/src/MPSegment.hpp
index f35158c..975998b 100644
--- a/src/MPSegment.hpp
+++ b/src/MPSegment.hpp
@@ -28,7 +28,7 @@ class MPSegment: public SegmentBase {
     }
   }
 
-  bool isUserDictSingleChineseWord(const Unicode::value_type & value) const {
+  bool isUserDictSingleChineseWord(const Rune & value) const {
     return dictTrie_->isUserDictSingleChineseWord(value);
   }
 
@@ -101,7 +101,7 @@ class MPSegment: public SegmentBase {
         res.push_back(p->word);
         i += p->word.size();
       } else { //single chinese word
-        res.push_back(Unicode(1, dags[i].uniCh));
+        res.push_back(Unicode(1, dags[i].rune));
         i++;
       }
     }
diff --git a/src/SegmentBase.hpp b/src/SegmentBase.hpp
index 9e6f4e4..93bc901 100644
--- a/src/SegmentBase.hpp
+++ b/src/SegmentBase.hpp
@@ -14,9 +14,9 @@ using namespace Limonp;
 
 //const char* const SPECIAL_CHARS = " \t\n";
 #ifndef CPPJIEBA_GBK
-const UnicodeValueType SPECIAL_SYMBOL[] = {32u, 9u, 10u, 12290u, 65292u};
+const Rune SPECIAL_SYMBOL[] = {32u, 9u, 10u, 12290u, 65292u};
 #else
-const UnicodeValueType SPECIAL_SYMBOL[] = {32u, 9u, 10u};
+const Rune SPECIAL_SYMBOL[] = {32u, 9u, 10u};
 #endif
 
 class SegmentBase: public ISegment, public NonCopyable {
@@ -63,7 +63,7 @@ class SegmentBase: public ISegment, public NonCopyable {
     assert(specialSymbols_.size());
   }
  private:
-  unordered_set<UnicodeValueType> specialSymbols_;
+  unordered_set<Rune> specialSymbols_;
 
 };
 }
diff --git a/src/TransCode.hpp b/src/TransCode.hpp
index 5c96978..d7fa162 100644
--- a/src/TransCode.hpp
+++ b/src/TransCode.hpp
@@ -12,8 +12,10 @@
 namespace CppJieba {
 
 using namespace Limonp;
-typedef uint16_t UnicodeValueType;
-typedef Limonp::LocalVector<UnicodeValueType> Unicode;
+
+typedef uint16_t Rune;
+typedef Limonp::LocalVector<Rune> Unicode;
+
 namespace TransCode {
 inline bool decode(const string& str, Unicode& res) {
 #ifdef CPPJIEBA_GBK
diff --git a/src/Trie.hpp b/src/Trie.hpp
index 289787b..c42c383 100644
--- a/src/Trie.hpp
+++ b/src/Trie.hpp
@@ -22,16 +22,16 @@ inline ostream & operator << (ostream& os, const DictUnit& unit) {
 }
 
 struct Dag {
-  uint16_t uniCh;
+  uint16_t rune;
   LocalVector<pair<size_t, const DictUnit*> > nexts;
   const DictUnit * pInfo;
   double weight;
   size_t nextPos;
-  Dag():uniCh(0), pInfo(NULL), weight(0.0), nextPos(0) {
+  Dag():rune(0), pInfo(NULL), weight(0.0), nextPos(0) {
   }
 };
 
-typedef Unicode::value_type TrieKey;
+typedef Rune TrieKey;
 
 class TrieNode {
  public :
@@ -90,9 +90,9 @@ class Trie {
     const TrieNode *ptNode = NULL;
     TrieNode::NextMap::const_iterator citer;
     for (size_t i = 0; i < size_t(end - begin); i++) {
-      Unicode::value_type ch = *(begin + i);
+      Rune ch = *(begin + i);
       ptNode = _base + ch;
-      res[i].uniCh = ch;
+      res[i].rune = ch;
       assert(res[i].nexts.empty());
 
       res[i].nexts.push_back(pair<size_t, const DictUnit*>(i, ptNode->ptValue));