diff --git a/lib/resty/etcd.lua b/lib/resty/etcd.lua
index 30ecc46c..71f604b6 100644
--- a/lib/resty/etcd.lua
+++ b/lib/resty/etcd.lua
@@ -1,22 +1,9 @@
 local etcdv3  = require("resty.etcd.v3")
 local typeof  = require("typeof")
-local require = require
-local pcall   = pcall
 
 local _M = {version = 0.9}
 
 
-local function require_serializer(serializer_name)
-    if serializer_name then
-        local ok, module = pcall(require, "resty.etcd.serializers." .. serializer_name)
-        if ok then
-            return module
-        end
-    end
-
-    return require("resty.etcd.serializers.json")
-end
-
 function _M.new(opts)
     opts = opts or {}
     if not typeof.table(opts) then
@@ -33,7 +20,7 @@ function _M.new(opts)
     opts.ttl  = opts.ttl or -1
 
     local serializer_name = typeof.string(opts.serializer) and opts.serializer
-    opts.serializer = require_serializer(serializer_name)
+    opts.serializer = serializer_name
     opts.api_prefix = "/v3"
 
     return etcdv3.new(opts)
diff --git a/lib/resty/etcd/v3.lua b/lib/resty/etcd/v3.lua
index c094e1fa..846c2900 100644
--- a/lib/resty/etcd/v3.lua
+++ b/lib/resty/etcd/v3.lua
@@ -1,4 +1,5 @@
 -- https://github.com/ledgetech/lua-resty-http
+local require       = require
 local split         = require("ngx.re").split
 local typeof        = require("typeof")
 local cjson         = require("cjson.safe")
@@ -27,6 +28,7 @@ local decode_base64 = ngx.decode_base64
 local semaphore     = require("ngx.semaphore")
 local health_check  = require("resty.etcd.health_check")
 local pl_path       = require("pl.path")
+local pcall         = pcall
 
 math.randomseed(now() * 1000 + ngx.worker.pid())
 
@@ -265,6 +267,17 @@ local function serialize_and_encode_base64(serialize_fn, data)
     return encode_base64(data)
 end
 
+local function require_serializer(serializer_name)
+    if serializer_name then
+        local ok, module = pcall(require, "resty.etcd.serializers." .. serializer_name)
+        if ok then
+            return module
+        end
+    end
+
+    return require("resty.etcd.serializers.json")
+end
+
 
 function _M.new(opts)
     local timeout    = opts.timeout
@@ -278,7 +291,7 @@ function _M.new(opts)
     if ssl_verify == nil then
         ssl_verify = true
     end
-    local serializer = opts.serializer
+    local serializer = require_serializer(opts.serializer)
     local extra_headers = opts.extra_headers
     local sni        = opts.sni
     local unix_socket_proxy = opts.unix_socket_proxy
diff --git a/t/v3/serializer.t b/t/v3/serializer.t
index 026020f7..998f6897 100644
--- a/t/v3/serializer.t
+++ b/t/v3/serializer.t
@@ -212,3 +212,59 @@ checked val as expect: 111
 checked val as expect: "foo"
 checked val as expect: {"a":1}
 checked val as expect: 
+
+=== TEST 5: resty.etcd.v3 serializer
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            local cjson = require("cjson.safe")
+
+            local etcd, err = require("resty.etcd.v3").new({
+                timeout = 5,
+                http_host = "http://127.0.0.1:2379",
+                ttl = -1,
+                api_prefix = "/v3",
+                serializer = "raw"
+            })
+            check_res(etcd, err)
+
+            local res
+            res, err = etcd:rmdir("/dir")
+            check_res(res, err, nil, 200)
+
+            res, err = etcd:set("/dir/v3/a", '"foo"')
+            check_res(res, err)
+
+            res, err = etcd:get("/dir/v3/a")
+            check_res(res, err, '"foo"')
+
+            local s = cjson.encode({a = 1})
+            res, err = etcd:setx("/dir/v3/a", s)
+            check_res(res, err, nil, 200)
+
+            res, err = etcd:get("/dir/v3/a")
+            check_res(res, err, s, 200)
+
+            res, err = etcd:setnx("/dir/v3/not_exist", "")
+            check_res(res, err, nil, 200)
+
+            res, err = etcd:get("/dir/v3/not_exist")
+            check_res(res, err, "", 200)
+
+            res, err = etcd:rmdir("/dir")
+            check_res(res, err, nil, 200)
+
+            res, err = etcd:set("/dir/v3/b", 111)
+            check_res(res, err)
+        }
+    }
+--- request
+GET /t
+--- no_error_log
+[error]
+--- response_body
+checked val as expect: "foo"
+checked val as expect: {"a":1}
+checked val as expect: 
+err: unsupported type for number