diff --git a/src/storage/s3.js b/src/storage/s3.js
index a93323f8b..a68fc7f6c 100644
--- a/src/storage/s3.js
+++ b/src/storage/s3.js
@@ -19,6 +19,7 @@ function getBackupCredentials(apiConfig, callback) {
     assert(apiConfig.accessKeyId && apiConfig.secretAccessKey);
 
     var credentials = {
+        signatureVersion: 'v4',
         accessKeyId: apiConfig.accessKeyId,
         secretAccessKey: apiConfig.secretAccessKey,
         region: apiConfig.region || 'us-east-1'