diff --git a/include/cppjieba/DictTrie.hpp b/include/cppjieba/DictTrie.hpp
index 1c428f6..26bbb2b 100644
--- a/include/cppjieba/DictTrie.hpp
+++ b/include/cppjieba/DictTrie.hpp
@@ -6,6 +6,7 @@
 #include <map>
 #include <string>
 #include <cstring>
+#include <cstdlib>
 #include <stdint.h>
 #include <cmath>
 #include <limits>
@@ -117,7 +118,7 @@ class DictTrie {
         } else {
           MakeNodeInfo(node_info, 
                 buf[0], 
-                (buf.size() == 2 ? std::stoi(buf[1], nullptr) : user_word_default_weight_),
+                (buf.size() == 2 ? atoi(buf[1].c_str()) : user_word_default_weight_),
                 (buf.size() == 3 ? buf[2] : buf[1]));
         }
         static_node_infos_.push_back(node_info);