diff --git a/lib/cmd/test.js b/lib/cmd/test.js
index 007dad28..19e60623 100644
--- a/lib/cmd/test.js
+++ b/lib/cmd/test.js
@@ -68,13 +68,7 @@ class TestCommand extends Command {
   }
 
   async run(context) {
-    const opt = {
-      env: Object.assign({
-        NODE_ENV: 'test',
-      }, context.env),
-      execArgv: context.execArgv,
-    };
-    const mochaFile = require.resolve('mocha/bin/_mocha');
+    const mochaFile = process.env.MOCHA_FILE || require.resolve('mocha/bin/_mocha');
     const testArgs = await this.formatTestArgs(context);
     if (!testArgs) return;
 
@@ -92,6 +86,12 @@ class TestCommand extends Command {
     }
 
     debug('run test: %s %s', mochaFile, testArgs.join(' '));
+    const opt = {
+      env: Object.assign({
+        NODE_ENV: 'test',
+      }, context.env),
+      execArgv: context.execArgv,
+    };
     await this.helper.forkNode(mochaFile, testArgs, opt);
   }
 
diff --git a/test/fixtures/bin/fake_mocha.js b/test/fixtures/bin/fake_mocha.js
new file mode 100644
index 00000000..b0ec8934
--- /dev/null
+++ b/test/fixtures/bin/fake_mocha.js
@@ -0,0 +1,2 @@
+console.log('env: ', process.env);
+console.log('argv: ', process.argv);
diff --git a/test/lib/cmd/test.test.js b/test/lib/cmd/test.test.js
index dd0b6cb5..31a46e16 100644
--- a/test/lib/cmd/test.test.js
+++ b/test/lib/cmd/test.test.js
@@ -342,4 +342,19 @@ describe('test/lib/cmd/test.test.js', () => {
       .expect('code', 0)
       .end();
   });
+
+  it('env should work', async () => {
+    mm(process.env, 'TESTS', 'test/**/*.test.js');
+    return coffee.fork(eggBin, [ 'test', '--parallel' ], {
+      cwd: path.join(__dirname, '../../fixtures/test-demo-app'),
+      env: Object.assign({
+        MOCHA_FILE: path.join(__dirname, '../../fixtures/bin/fake_mocha.js'),
+      }, process.env),
+    })
+      // .debug()
+      .expect('stdout', /AUTO_AGENT: 'true'/)
+      .expect('stdout', /ENABLE_MOCHA_PARALLEL: 'true'/)
+      .expect('code', 0)
+      .end();
+  });
 });