diff --git a/lib/cmd/cov.js b/lib/cmd/cov.js
index 949e0d71..d52be79a 100644
--- a/lib/cmd/cov.js
+++ b/lib/cmd/cov.js
@@ -45,12 +45,18 @@ class CovCommand extends Command {
 
     // ignore coverage
     if (argv.x) {
-      this[EXCLUDES].add(argv.x);
+      if (Array.isArray(argv.x)) {
+        for (const exclude of argv.x) {
+          this.addExclude(exclude);
+        }
+      } else {
+        this.addExclude(argv.x);
+      }
       argv.x = undefined;
     }
     const excludes = (process.env.COV_EXCLUDES && process.env.COV_EXCLUDES.split(',')) || [];
     for (const exclude of excludes) {
-      this[EXCLUDES].add(exclude);
+      this.addExclude(exclude);
     }
 
     const nycCli = require.resolve('nyc/bin/nyc.js');
diff --git a/test/fixtures/mocha-test/test/foo.test.js b/test/fixtures/mocha-test/test/foo.test.js
new file mode 100644
index 00000000..224222ae
--- /dev/null
+++ b/test/fixtures/mocha-test/test/foo.test.js
@@ -0,0 +1,9 @@
+'use strict';
+
+const assert = require('assert');
+
+describe('mocha-test', () => {
+  it('should work', () => {
+    assert(true);
+  });
+});
diff --git a/test/lib/cmd/cov.test.js b/test/lib/cmd/cov.test.js
index ac7d4e27..4c5f58d1 100644
--- a/test/lib/cmd/cov.test.js
+++ b/test/lib/cmd/cov.test.js
@@ -16,7 +16,7 @@ describe('test/lib/cmd/cov.test.js', () => {
     mm(process.env, 'TESTS', 'test/**/*.test.js');
     mm(process.env, 'NYC_CWD', cwd);
     const child = coffee.fork(eggBin, [ 'cov' ], { cwd })
-      .debug()
+      // .debug()
       .expect('stdout', /should success/)
       .expect('stdout', /a\.test\.js/)
       .expect('stdout', /b[\/|\\]b\.test\.js/)
@@ -62,15 +62,42 @@ describe('test/lib/cmd/cov.test.js', () => {
     assert(!/ignore[\/|\\]a.js/.test(lcov));
   });
 
-  it('should success with -x to ignore files', function* () {
-    yield coffee.fork(eggBin, [ 'cov', '-x', 'ignore/*', 'test/**/*.test.js' ], { cwd })
+  it('should success with -x to ignore one dirs', function* () {
+    const child = coffee.fork(eggBin, [ 'cov', '-x', 'ignore/', 'test/**/*.test.js' ], { cwd })
       // .debug()
       .expect('stdout', /should success/)
       .expect('stdout', /a\.test\.js/)
       .expect('stdout', /b[\/|\\]b\.test\.js/)
-      .notExpect('stdout', /a.js/)
-      // .expect('stdout', /Statements {3}: 75% \( 3[\/|\\]4 \)/)
-      .expect('code', 0)
+      .notExpect('stdout', /a.js/);
+
+    // only test on npm run test
+    if (!process.env.NYC_ROOT_ID) {
+      child.expect('stdout', /Statements {3}: 75% \( 3[\/|\\]4 \)/);
+    }
+
+    yield child.expect('code', 0)
+      .end();
+    assert(fs.existsSync(path.join(cwd, 'coverage/coverage-final.json')));
+    assert(fs.existsSync(path.join(cwd, 'coverage/lcov-report/index.html')));
+    assert(fs.existsSync(path.join(cwd, 'coverage/lcov.info')));
+    const lcov = fs.readFileSync(path.join(cwd, 'coverage/lcov.info'), 'utf8');
+    assert(!/ignore[\/|\\]a.js/.test(lcov));
+  });
+
+  it('should success with -x to ignore multi dirs', function* () {
+    const child = coffee.fork(eggBin, [ 'cov', '-x', 'ignore2/*', '-x', 'ignore/', 'test/**/*.test.js' ], { cwd })
+      // .debug()
+      .expect('stdout', /should success/)
+      .expect('stdout', /a\.test\.js/)
+      .expect('stdout', /b[\/|\\]b\.test\.js/)
+      .notExpect('stdout', /a.js/);
+
+    // only test on npm run test
+    if (!process.env.NYC_ROOT_ID) {
+      child.expect('stdout', /Statements {3}: 75% \( 3[\/|\\]4 \)/);
+    }
+
+    yield child.expect('code', 0)
       .end();
     assert(fs.existsSync(path.join(cwd, 'coverage/coverage-final.json')));
     assert(fs.existsSync(path.join(cwd, 'coverage/lcov-report/index.html')));
diff --git a/test/mocha-bin.test.js b/test/mocha-bin.test.js
new file mode 100644
index 00000000..911949ad
--- /dev/null
+++ b/test/mocha-bin.test.js
@@ -0,0 +1,17 @@
+'use strict';
+
+const path = require('path');
+const coffee = require('coffee');
+
+describe('test/mocha-bin.test.js', () => {
+  const mochaBin = require.resolve('../bin/mocha.js');
+  const cwd = path.join(__dirname, 'fixtures/mocha-test');
+
+  it('should test with mocha', () => {
+    return coffee.fork(mochaBin, [ 'test/*.test.js' ], { cwd })
+      .debug()
+      .expect('stdout', /1 passing/)
+      .expect('code', 0)
+      .end();
+  });
+});