diff --git a/lib/cmd/cov.js b/lib/cmd/cov.js
index 2dc2b9b1..c2dad72f 100644
--- a/lib/cmd/cov.js
+++ b/lib/cmd/cov.js
@@ -80,6 +80,7 @@ class CovCommand extends Command {
 
     // save coverage-xxxx.json to $PWD/coverage
     const covArgs = this.getCovArgs(context);
+    if (!covArgs) return;
     debug('covArgs: %j', covArgs);
     yield this.helper.forkNode(nycCli, covArgs, opt);
   }
@@ -120,7 +121,9 @@ class CovCommand extends Command {
       covArgs.push(exclude);
     }
     covArgs.push(require.resolve('mocha/bin/_mocha'));
-    covArgs = covArgs.concat(this.formatTestArgs(context));
+    const testArgs = this.formatTestArgs(context);
+    if (!testArgs) return;
+    covArgs = covArgs.concat(testArgs);
     return covArgs;
   }
 }
diff --git a/lib/cmd/test.js b/lib/cmd/test.js
index 33317d79..7045b289 100644
--- a/lib/cmd/test.js
+++ b/lib/cmd/test.js
@@ -45,6 +45,7 @@ class TestCommand extends Command {
     };
     const mochaFile = require.resolve('mocha/bin/_mocha');
     const testArgs = this.formatTestArgs(context);
+    if (!testArgs) return;
     debug('run test: %s %s', mochaFile, testArgs.join(' '));
     yield this.helper.forkNode(mochaFile, testArgs, opt);
   }
@@ -95,15 +96,21 @@ class TestCommand extends Command {
     testArgv.require = requireArr;
 
     // collect test files
-    let files = testArgv._.slice();
-    if (!files.length) {
-      files = [ process.env.TESTS || `test/**/*.test.${testArgv.typescript ? 'ts' : 'js'}` ];
+    let pattern = testArgv._.slice();
+    if (!pattern.length) {
+      pattern = [ process.env.TESTS || `test/**/*.test.${testArgv.typescript ? 'ts' : 'js'}` ];
     }
+    pattern = pattern.concat([ '!test/fixtures', '!test/node_modules' ]);
 
     // expand glob and skip node_modules and fixtures
-    files = globby.sync(files.concat([ '!test/fixtures', '!test/node_modules' ]));
+    const files = globby.sync(pattern);
     files.sort();
 
+    if (files.length === 0) {
+      console.log(`No test files found with ${pattern}`);
+      return;
+    }
+
     // auto add setup file as the first test file
     const setupFile = path.join(process.cwd(), 'test/.setup.js');
     if (fs.existsSync(setupFile)) {
diff --git a/test/lib/cmd/cov.test.js b/test/lib/cmd/cov.test.js
index 16064e51..5558ba55 100644
--- a/test/lib/cmd/cov.test.js
+++ b/test/lib/cmd/cov.test.js
@@ -41,6 +41,15 @@ describe('test/lib/cmd/cov.test.js', () => {
     if (!process.env.NYC_ROOT_ID) assertCoverage(cwd);
   });
 
+  it('should exit when not test files', done => {
+    mm(process.env, 'NYC_CWD', cwd);
+    coffee.fork(eggBin, [ 'cov', 'test/**/*.nth.js' ], { cwd })
+      // .debug()
+      .expect('stdout', /No test files found/)
+      .expect('code', 0)
+      .end(done);
+  });
+
   it('should hotfixSpawnWrap success on mock windows', function* () {
     mm(process.env, 'TESTS', 'test/**/*.test.js');
     mm(process.env, 'NYC_CWD', cwd);
@@ -173,6 +182,7 @@ describe('test/lib/cmd/cov.test.js', () => {
   });
 
   it('should set EGG_BIN_PREREQUIRE', function* () {
+    mm(process.env, 'TESTS', 'test/**/*.test.js');
     const cwd = path.join(__dirname, '../../fixtures/prerequire');
     yield coffee.fork(eggBin, [ 'cov' ], { cwd })
       // .debug()
diff --git a/test/lib/cmd/test.test.js b/test/lib/cmd/test.test.js
index 304a1759..b7f76bb5 100644
--- a/test/lib/cmd/test.test.js
+++ b/test/lib/cmd/test.test.js
@@ -55,6 +55,14 @@ describe('test/lib/cmd/test.test.js', () => {
       .end(done);
   });
 
+  it('should exit when not test files', done => {
+    coffee.fork(eggBin, [ 'test', 'test/**/*.nth.js' ], { cwd })
+      // .debug()
+      .expect('stdout', /No test files found/)
+      .expect('code', 0)
+      .end(done);
+  });
+
   it('should use process.env.TEST_REPORTER', done => {
     mm(process.env, 'TESTS', 'test/**/*.test.js');
     mm(process.env, 'TEST_REPORTER', 'json');