diff --git a/package.json b/package.json
index af4c0c06..ec983ce8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "node-kakao",
-  "version": "3.1.3",
+  "version": "3.1.4",
   "description": "Loco protocol compatible library",
   "main": "dist/index.js",
   "scripts": {
diff --git a/src/api/web-api-client.ts b/src/api/web-api-client.ts
index d775f095..3316e4a4 100644
--- a/src/api/web-api-client.ts
+++ b/src/api/web-api-client.ts
@@ -79,7 +79,7 @@ export abstract class WebApiClient implements ApiHeaderDecorator {
         if (form) {
             let formData = this.convertToFormData(form);
 
-            reqData.data = formData;
+            reqData.data = formData.toString();
         }
 
         let res = JsonUtil.parseLoseless((await Axios.request(reqData)).data);
diff --git a/src/config/client-config-provider.ts b/src/config/client-config-provider.ts
index 4b5c255c..95a3442d 100644
--- a/src/config/client-config-provider.ts
+++ b/src/config/client-config-provider.ts
@@ -17,7 +17,7 @@ export class DefaultClientConfigProvider implements ClientConfigProvider {
     private configuration: ClientConfig;
 
     constructor(config?: Partial<ClientConfig>) {
-        this.configuration = config ? Object.assign(config, DefaultConfiguration) : DefaultConfiguration;
+        this.configuration = config ? Object.assign(DefaultConfiguration, config) : DefaultConfiguration;
     }
 
     get Configuration() {