diff --git a/python/msgpack/unpack.h b/python/msgpack/unpack.h
index cc48d9c7..12afb998 100644
--- a/python/msgpack/unpack.h
+++ b/python/msgpack/unpack.h
@@ -23,9 +23,7 @@
 #define MSGPACK_MAX_STACK_SIZE  (1024)
 #include "unpack_define.h"
 
-using namespace std;
-
-typedef map<string, PyObject*> str_cach_t;
+typedef std::map<std::string, PyObject*> str_cach_t;
 struct unpack_user {
     str_cach_t strcache;
 
@@ -127,7 +125,7 @@ static inline int template_callback_map_item(unpack_user* u, msgpack_unpack_obje
 static inline int template_callback_raw(unpack_user* u, const char* b, const char* p, unsigned int l, msgpack_unpack_object* o)
 {
     if (l < 16) {
-        string s(p, l);
+        std::string s(p, l);
         str_cach_t ::iterator it = u->strcache.find(s);
         if (it != u->strcache.end()) {
             *o = it->second;
diff --git a/python/msgpack/unpack_template.h b/python/msgpack/unpack_template.h
index db333689..c960c3ab 100644
--- a/python/msgpack/unpack_template.h
+++ b/python/msgpack/unpack_template.h
@@ -43,10 +43,13 @@
 
 msgpack_unpack_struct_decl(_stack) {
 	msgpack_unpack_object obj;
-    size_t curr;
 	size_t count;
 	unsigned int ct;
-	msgpack_unpack_object map_key;
+
+    union {
+        size_t curr;
+        msgpack_unpack_object map_key;
+    };
 };
 
 msgpack_unpack_struct_decl(_context) {