diff --git a/src/json.cc b/src/json.cc
index 825d5905..6dd35f43 100644
--- a/src/json.cc
+++ b/src/json.cc
@@ -521,84 +521,6 @@ std::string jsonEscape(const std::string& s)
   return t;
 }
 
-std::string encode(const ValueBase* vlb)
-{
-  class JsonValueBaseVisitor:public ValueBaseVisitor {
-  private:
-    std::ostringstream out_;
-  public:
-    virtual void visit(const String& string)
-    {
-      const std::string& s = string.s();
-      std::string t = jsonEscape(s);
-      out_ << '"';
-      out_.write(t.data(), t.size());
-      out_ << '"';
-    }
-
-    virtual void visit(const Integer& integer)
-    {
-      out_ << integer.i();
-    }
-
-    virtual void visit(const Bool& boolValue)
-    {
-      out_ << (boolValue.val() ? "true" : "false");
-    }
-
-    virtual void visit(const Null& nullValue)
-    {
-      out_ << "null";
-    }
-
-    virtual void visit(const List& list)
-    {
-      out_ << '[';
-      List::ValueType::const_iterator i = list.begin();
-      if(!list.empty()) {
-        (*i)->accept(*this);
-      }
-      ++i;
-      for(List::ValueType::const_iterator eoi = list.end(); i != eoi; ++i){
-        out_ << ',';
-        (*i)->accept(*this);
-      }
-      out_ << ']';
-    }
-
-    virtual void visit(const Dict& dict)
-    {
-      out_ << '{';
-      Dict::ValueType::const_iterator i = dict.begin();
-      if(!dict.empty()) {
-        std::string key = jsonEscape((*i).first);
-        out_ << '"';
-        out_.write(key.data(), key.size());
-        out_ << "\":";
-        (*i).second->accept(*this);
-      }
-      ++i;
-      for(Dict::ValueType::const_iterator eoi = dict.end(); i != eoi; ++i){
-        out_ << ',';
-        std::string key = jsonEscape((*i).first);
-        out_ << '"';
-        out_.write(key.data(), key.size());
-        out_ << "\":";
-        (*i).second->accept(*this);
-      }
-      out_ << '}';
-    }
-
-    std::string getResult() const
-    {
-      return out_.str();
-    }
-  };
-  JsonValueBaseVisitor visitor;
-  vlb->accept(visitor);
-  return visitor.getResult();
-}
-
 // Serializes JSON object or array.
 std::string encode(const SharedHandle<ValueBase>& json)
 {
diff --git a/src/json.h b/src/json.h
index 932fe3a9..3a106fdd 100644
--- a/src/json.h
+++ b/src/json.h
@@ -127,7 +127,6 @@ OutputStream& encode(OutputStream& out, const SharedHandle<ValueBase>& vlb)
 }
 
 // Serializes JSON object or array.
-std::string encode(const ValueBase* json);
 std::string encode(const SharedHandle<ValueBase>& json);
 
 struct JsonGetParam {
diff --git a/test/JsonTest.cc b/test/JsonTest.cc
index 8c81a44c..971982ff 100644
--- a/test/JsonTest.cc
+++ b/test/JsonTest.cc
@@ -413,43 +413,43 @@ void JsonTest::testDecode_error()
 void JsonTest::testEncode()
 {
   {
-    Dict dict;
-    dict["name"] = String::g("aria2");
-    dict["loc"] = Integer::g(80000);
+    SharedHandle<Dict> dict = Dict::g();
+    dict->put("name", String::g("aria2"));
+    dict->put("loc", Integer::g(80000));
     SharedHandle<List> files = List::g();
     files->append(String::g("aria2c"));
-    dict["files"] = files;
+    dict->put("files", files);
     SharedHandle<Dict> attrs = Dict::g();
     attrs->put("license", String::g("GPL"));
-    dict["attrs"] = attrs;
+    dict->put("attrs", attrs);
 
     CPPUNIT_ASSERT_EQUAL(std::string("{\"attrs\":{\"license\":\"GPL\"},"
                                      "\"files\":[\"aria2c\"],"
                                      "\"loc\":80000,"
                                      "\"name\":\"aria2\"}"),
-                         json::encode(&dict));
+                         json::encode(dict));
   }
   {
-    List list;
-    list.append("\"\\/\b\f\n\r\t");
+    SharedHandle<List> list = List::g();
+    list->append("\"\\/\b\f\n\r\t");
     CPPUNIT_ASSERT_EQUAL(std::string("[\"\\\"\\\\\\/\\b\\f\\n\\r\\t\"]"),
-                         json::encode(&list));
+                         json::encode(list));
   }
   {
-    List list;
+    SharedHandle<List> list = List::g();
     std::string s;
     s += 0x1Fu;
-    list.append(s);
+    list->append(s);
     CPPUNIT_ASSERT_EQUAL(std::string("[\"\\u001F\"]"),
-                         json::encode(&list));
+                         json::encode(list));
   }
   {
-    List list;
-    list.append(Bool::gTrue());
-    list.append(Bool::gFalse());
-    list.append(Null::g());
+    SharedHandle<List> list = List::g();
+    list->append(Bool::gTrue());
+    list->append(Bool::gFalse());
+    list->append(Null::g());
     CPPUNIT_ASSERT_EQUAL(std::string("[true,false,null]"),
-                         json::encode(&list));
+                         json::encode(list));
   }
 }