diff --git a/lib/core/mergeConfig.js b/lib/core/mergeConfig.js
index 1da9040..6097a3e 100644
--- a/lib/core/mergeConfig.js
+++ b/lib/core/mergeConfig.js
@@ -37,7 +37,8 @@ module.exports = function mergeConfig(config1, config2) {
     'baseURL', 'transformRequest', 'transformResponse', 'paramsSerializer',
     'timeout', 'withCredentials', 'adapter', 'responseType', 'xsrfCookieName',
     'xsrfHeaderName', 'onUploadProgress', 'onDownloadProgress', 'maxContentLength',
-    'validateStatus', 'maxRedirects', 'httpAgent', 'httpsAgent', 'cancelToken'
+    'validateStatus', 'maxRedirects', 'httpAgent', 'httpsAgent', 'cancelToken',
+    'socketPath'
   ], function defaultToConfig2(prop) {
     if (typeof config2[prop] !== 'undefined') {
       config[prop] = config2[prop];