diff --git a/lib/plugins/aws/deploy/lib/checkForChanges.js b/lib/plugins/aws/deploy/lib/checkForChanges.js
index bbc7bc0e5..aa2479e65 100644
--- a/lib/plugins/aws/deploy/lib/checkForChanges.js
+++ b/lib/plugins/aws/deploy/lib/checkForChanges.js
@@ -109,23 +109,24 @@ module.exports = {
       // create hashes for all the zip files
       const zipFiles = globby.sync(['**.zip'], { cwd: serverlessDirPath, dot: true, silent: true });
       const zipFilePaths = zipFiles.map((zipFile) => path.join(serverlessDirPath, zipFile));
-      const zipFileHashes = zipFilePaths.map((zipFilePath) => {
-        // TODO refactor to be async (use util function to compute checksum async)
-        const zipFile = fs.readFileSync(zipFilePath);
-        return crypto.createHash('sha256').update(zipFile).digest('base64');
+
+      const readFile = BbPromise.promisify(fs.readFile);
+      const zipFileHashesPromises = zipFilePaths.map(zipFilePath => readFile(zipFilePath)
+        .then(zipFile => crypto.createHash('sha256').update(zipFile).digest('base64')));
+
+      return BbPromise.all(zipFileHashesPromises).then(zipFileHashes => {
+        const localHashes = zipFileHashes;
+        localHashes.push(localCfHash);
+
+        if (_.isEqual(remoteHashes.sort(), localHashes.sort())) {
+          this.serverless.service.provider.shouldNotDeploy = true;
+
+          const message = [
+            'Service files not changed. Skipping deployment...',
+          ].join('');
+          this.serverless.cli.log(message);
+        }
       });
-
-      const localHashes = zipFileHashes;
-      localHashes.push(localCfHash);
-
-      if (_.isEqual(remoteHashes.sort(), localHashes.sort())) {
-        this.serverless.service.provider.shouldNotDeploy = true;
-
-        const message = [
-          'Service files not changed. Skipping deployment...',
-        ].join('');
-        this.serverless.cli.log(message);
-      }
     }
 
     return BbPromise.resolve();
diff --git a/lib/plugins/aws/deploy/lib/checkForChanges.test.js b/lib/plugins/aws/deploy/lib/checkForChanges.test.js
index 4a8e9fb4f..1e4b013d6 100644
--- a/lib/plugins/aws/deploy/lib/checkForChanges.test.js
+++ b/lib/plugins/aws/deploy/lib/checkForChanges.test.js
@@ -278,7 +278,7 @@ describe('checkForChanges', () => {
   describe('#checkIfDeploymentIsNecessary()', () => {
     let normalizeCloudFormationTemplateStub;
     let globbySyncStub;
-    let readFileSyncStub;
+    let readFileStub;
 
     beforeEach(() => {
       normalizeCloudFormationTemplateStub = sinon
@@ -286,22 +286,22 @@ describe('checkForChanges', () => {
         .returns();
       globbySyncStub = sinon
         .stub(globby, 'sync');
-      readFileSyncStub = sinon
-        .stub(fs, 'readFileSync')
-        .returns();
+      readFileStub = sinon
+        .stub(fs, 'readFile')
+        .yields(null, undefined);
     });
 
     afterEach(() => {
       normalizeFiles.normalizeCloudFormationTemplate.restore();
       globby.sync.restore();
-      fs.readFileSync.restore();
+      fs.readFile.restore();
     });
 
     it('should resolve if no input is provided', () => expect(awsDeploy
       .checkIfDeploymentIsNecessary()).to.be.fulfilled.then(() => {
         expect(normalizeCloudFormationTemplateStub).to.not.have.been.called;
         expect(globbySyncStub).to.not.have.been.called;
-        expect(readFileSyncStub).to.not.have.been.called;
+        expect(readFileStub).to.not.have.been.called;
         expect(awsDeploy.serverless.cli.log).to.not.have.been.called;
       })
     );
@@ -313,7 +313,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.not.have.been.called;
           expect(globbySyncStub).to.not.have.been.called;
-          expect(readFileSyncStub).to.not.have.been.called;
+          expect(readFileStub).to.not.have.been.called;
           expect(awsDeploy.serverless.cli.log).to.not.have.been.called;
         });
     });
@@ -333,7 +333,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledOnce;
           expect(globbySyncStub).to.have.been.calledOnce;
-          expect(readFileSyncStub).to.have.been.calledOnce;
+          expect(readFileStub).to.have.been.calledOnce;
           expect(awsDeploy.serverless.cli.log).to.not.have.been.called;
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledWithExactly(
             awsDeploy.serverless.service.provider.compiledCloudFormationTemplate
@@ -346,7 +346,7 @@ describe('checkForChanges', () => {
               silent: true,
             }
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/my-service.zip')
           );
           expect(awsDeploy.serverless.service.provider.shouldNotDeploy).to.equal(undefined);
@@ -367,7 +367,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledOnce;
           expect(globbySyncStub).to.have.been.calledOnce;
-          expect(readFileSyncStub).to.have.been.calledOnce;
+          expect(readFileStub).to.have.been.calledOnce;
           expect(awsDeploy.serverless.cli.log).to.not.have.been.called;
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledWithExactly(
             awsDeploy.serverless.service.provider.compiledCloudFormationTemplate
@@ -380,7 +380,7 @@ describe('checkForChanges', () => {
               silent: true,
             }
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/my-service.zip')
           );
           expect(awsDeploy.serverless.service.provider.shouldNotDeploy).to.equal(undefined);
@@ -403,7 +403,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledOnce;
           expect(globbySyncStub).to.have.been.calledOnce;
-          expect(readFileSyncStub).to.have.been.calledTwice;
+          expect(readFileStub).to.have.been.calledTwice;
           expect(awsDeploy.serverless.cli.log).to.not.have.been.called;
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledWithExactly(
             awsDeploy.serverless.service.provider.compiledCloudFormationTemplate
@@ -416,10 +416,10 @@ describe('checkForChanges', () => {
               silent: true,
             }
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/func1.zip')
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/func2.zip')
           );
           expect(awsDeploy.serverless.service.provider.shouldNotDeploy).to.equal(undefined);
@@ -440,7 +440,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledOnce;
           expect(globbySyncStub).to.have.been.calledOnce;
-          expect(readFileSyncStub).to.have.been.calledOnce;
+          expect(readFileStub).to.have.been.calledOnce;
           expect(awsDeploy.serverless.cli.log).to.have.been.calledOnce;
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledWithExactly(
             awsDeploy.serverless.service.provider.compiledCloudFormationTemplate
@@ -453,7 +453,7 @@ describe('checkForChanges', () => {
               silent: true,
             }
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/my-service.zip')
           );
           expect(awsDeploy.serverless.service.provider.shouldNotDeploy).to.equal(true);
@@ -477,7 +477,7 @@ describe('checkForChanges', () => {
         .to.be.fulfilled.then(() => {
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledOnce;
           expect(globbySyncStub).to.have.been.calledOnce;
-          expect(readFileSyncStub).to.have.been.calledTwice;
+          expect(readFileStub).to.have.been.calledTwice;
           expect(awsDeploy.serverless.cli.log).to.have.been.calledOnce;
           expect(normalizeCloudFormationTemplateStub).to.have.been.calledWithExactly(
             awsDeploy.serverless.service.provider.compiledCloudFormationTemplate
@@ -490,10 +490,10 @@ describe('checkForChanges', () => {
               silent: true,
             }
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/func1.zip')
           );
-          expect(readFileSyncStub).to.have.been.calledWithExactly(
+          expect(readFileStub).to.have.been.calledWith(
             path.join('my-service/.serverless/func2.zip')
           );
           expect(awsDeploy.serverless.service.provider.shouldNotDeploy).to.equal(true);