diff --git a/lib/core/config.js b/lib/core/config.js
index f5bfde92..18ad623d 100644
--- a/lib/core/config.js
+++ b/lib/core/config.js
@@ -148,6 +148,7 @@ Config.prototype._mergeConfig = function(configFilePath, defaultConfig, env, ena
 
   let config;
   if (fs.existsSync(configFilePath + '.js')) {
+    delete require.cache[fs.dappPath(configFilePath + '.js')];
     config = require(fs.dappPath(configFilePath + '.js'));
   } else {
     config = fs.readJSONSync(configFilePath + '.json');