diff --git a/lib/cmd/dev.js b/lib/cmd/dev.js
index 1292475a..a187ee26 100644
--- a/lib/cmd/dev.js
+++ b/lib/cmd/dev.js
@@ -42,9 +42,13 @@ class DevCommand extends Command {
 
   * run(context) {
     const devArgs = yield this.formatArgs(context);
+    const env = {
+      NODE_ENV: 'development',
+      EGG_MASTER_CLOSE_TIMEOUT: 1000,
+    };
     const options = {
       execArgv: context.execArgv,
-      env: Object.assign({ NODE_ENV: 'development' }, context.env),
+      env: Object.assign(env, context.env),
     };
     debug('%s %j %j, %j', this.serverBin, devArgs, options.execArgv, options.env.NODE_ENV);
     yield this.helper.forkNode(this.serverBin, devArgs, options);