diff --git a/bitcoinrpc/authproxy.py b/bitcoinrpc/authproxy.py
index 6d84fd3..5896db1 100644
--- a/bitcoinrpc/authproxy.py
+++ b/bitcoinrpc/authproxy.py
@@ -72,10 +72,22 @@ def __repr__(self):
         return '<%s \'%s\'>' % (self.__class__.__name__, self)
 
 
-def EncodeDecimal(o):
-    if isinstance(o, decimal.Decimal):
-        return float(round(o, 8))
-    raise TypeError(repr(o) + " is not JSON serializable")
+class DecimalEncoder(float):
+    def __init__(self, o):
+        self.o = o
+    def __repr__(self):
+        return str(self.o)
+
+class JSONEncoderWithDecimalCls(json.JSONEncoder):
+    def default(self, o):
+        if isinstance(o, decimal.Decimal):
+            return DecimalEncoder(o)
+        return json.JSONEncoder.default(self, o)
+
+JSONEncoderWithDecimal = JSONEncoderWithDecimalCls()
+
+def jsondumps(o):
+    return ''.join(JSONEncoderWithDecimal.iterencode(o))
 
 class AuthServiceProxy(object):
     __id_count = 0
@@ -124,11 +136,11 @@ def __call__(self, *args):
         AuthServiceProxy.__id_count += 1
 
         log.debug("-%s-> %s %s"%(AuthServiceProxy.__id_count, self.__service_name,
-                                 json.dumps(args, default=EncodeDecimal)))
-        postdata = json.dumps({'version': '1.1',
+                                 jsondumps(args)))
+        postdata = jsondumps({'version': '1.1',
                                'method': self.__service_name,
                                'params': args,
-                               'id': AuthServiceProxy.__id_count}, default=EncodeDecimal)
+                               'id': AuthServiceProxy.__id_count})
         self.__conn.request('POST', self.__url.path, postdata,
                             {'Host': self.__url.hostname,
                              'User-Agent': USER_AGENT,
@@ -157,7 +169,7 @@ def batch_(self, rpc_calls):
             m = rpc_call.pop(0)
             batch_data.append({"jsonrpc":"2.0", "method":m, "params":rpc_call, "id":AuthServiceProxy.__id_count})
 
-        postdata = json.dumps(batch_data, default=EncodeDecimal)
+        postdata = jsondumps(batch_data)
         log.debug("--> "+postdata)
         self.__conn.request('POST', self.__url.path, postdata,
                             {'Host': self.__url.hostname,
@@ -185,7 +197,7 @@ def _get_response(self):
         responsedata = http_response.read().decode('utf8')
         response = json.loads(responsedata, parse_float=decimal.Decimal)
         if "error" in response and response["error"] is None:
-            log.debug("<-%s- %s"%(response["id"], json.dumps(response["result"], default=EncodeDecimal)))
+            log.debug("<-%s- %s"%(response["id"], jsondumps(response["result"])))
         else:
             log.debug("<-- "+responsedata)
         return response