diff --git a/lib/reporter.js b/lib/reporter.js
index fe40359..ac923b1 100644
--- a/lib/reporter.js
+++ b/lib/reporter.js
@@ -11,6 +11,7 @@
 // ------------
 
 var path = require('path')
+const { promisify } = require('util')
 var istanbulLibCoverage = require('istanbul-lib-coverage')
 var istanbulLibReport = require('istanbul-lib-report')
 var minimatch = require('minimatch')
@@ -264,10 +265,12 @@ var CoverageReporter = function (rootConfig, helper, logger, emitter) {
       return
     }
 
-    helper.mkdirIfNotExists(outputPath, function () {
-      log.debug('Writing coverage to %s', outputPath)
-      report.execute(context)
-    })
+    const mkdirIfNotExists = promisify(helper.mkdirIfNotExists)
+    await mkdirIfNotExists(outputPath)
+
+    log.debug('Writing coverage to %s', outputPath)
+    report.execute(context)
+
     return results
   }
 
diff --git a/test/reporter.spec.js b/test/reporter.spec.js
index c6138e2..a7f5834 100644
--- a/test/reporter.spec.js
+++ b/test/reporter.spec.js
@@ -27,7 +27,10 @@ describe('reporter', () => {
   const mockHelper = {
     isDefined: (v) => helper.isDefined(v),
     merge: (...arg) => helper.merge(...arg),
-    mkdirIfNotExists: mkdirIfNotExistsStub,
+    mkdirIfNotExists: (dir, done) => {
+      mkdirIfNotExistsStub(dir, done)
+      setTimeout(done, 0)
+    },
     normalizeWinPath: (path) => helper.normalizeWinPath(path)
   }
 
@@ -166,7 +169,6 @@ describe('reporter', () => {
       const dir = rootConfig.coverageReporter.dir
       expect(mkdirIfNotExistsStub.getCall(0).args[0]).to.deep.equal(resolve('/base', dir, fakeChrome.name))
       expect(mkdirIfNotExistsStub.getCall(1).args[0]).to.deep.equal(resolve('/base', dir, fakeOpera.name))
-      mkdirIfNotExistsStub.getCall(0).args[1]()
       expect(reportCreateStub).to.have.been.called
       expect(mockPackageSummary.execute).to.have.been.called
       const createArgs = reportCreateStub.getCall(0).args
@@ -192,7 +194,6 @@ describe('reporter', () => {
       const subdir = customConfig.coverageReporter.subdir
       expect(mkdirIfNotExistsStub.getCall(0).args[0]).to.deep.equal(resolve('/base', dir, subdir))
       expect(mkdirIfNotExistsStub.getCall(1).args[0]).to.deep.equal(resolve('/base', dir, subdir))
-      mkdirIfNotExistsStub.getCall(0).args[1]()
       expect(reportCreateStub).to.have.been.called
       expect(mockPackageSummary.execute).to.have.been.called
     })
@@ -213,7 +214,6 @@ describe('reporter', () => {
       const dir = customConfig.coverageReporter.dir
       expect(mkdirIfNotExistsStub.getCall(0).args[0]).to.deep.equal(resolve('/base', dir, 'chrome'))
       expect(mkdirIfNotExistsStub.getCall(1).args[0]).to.deep.equal(resolve('/base', dir, 'opera'))
-      mkdirIfNotExistsStub.getCall(0).args[1]()
       expect(reportCreateStub).to.have.been.called
       expect(mockPackageSummary.execute).to.have.been.called
     })
@@ -246,7 +246,6 @@ describe('reporter', () => {
       expect(mkdirIfNotExistsStub.getCall(1).args[0]).to.deep.equal(resolve('/base', 'reporter1', 'opera'))
       expect(mkdirIfNotExistsStub.getCall(2).args[0]).to.deep.equal(resolve('/base', 'reporter2', 'CHROME'))
       expect(mkdirIfNotExistsStub.getCall(3).args[0]).to.deep.equal(resolve('/base', 'reporter2', 'OPERA'))
-      mkdirIfNotExistsStub.getCall(0).args[1]()
       expect(reportCreateStub).to.have.been.called
       expect(mockPackageSummary.execute).to.have.been.called
     })
@@ -277,7 +276,6 @@ describe('reporter', () => {
       expect(mkdirIfNotExistsStub.getCall(1).args[0]).to.deep.equal(resolve('/base', 'reporter1', 'defaultsubdir'))
       expect(mkdirIfNotExistsStub.getCall(2).args[0]).to.deep.equal(resolve('/base', 'defaultdir', 'CHROME'))
       expect(mkdirIfNotExistsStub.getCall(3).args[0]).to.deep.equal(resolve('/base', 'defaultdir', 'OPERA'))
-      mkdirIfNotExistsStub.getCall(0).args[1]()
       expect(reportCreateStub).to.have.been.called
       expect(mockPackageSummary.execute).to.have.been.called
     })