diff --git a/src/storage/s3.js b/src/storage/s3.js
index 50dac9a73..ab45abafe 100644
--- a/src/storage/s3.js
+++ b/src/storage/s3.js
@@ -65,7 +65,7 @@ function getS3Config(apiConfig, callback) {
         region: apiConfig.region || 'us-east-1',
         maxRetries: 10,
         retryDelayOptions: {
-            customBackoff: () => 20000 // constant backoff - https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/Config.html#retryDelayOptions-property
+            customBackoff: (/* retryCount, error */) => 20000 // constant backoff - https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/Config.html#retryDelayOptions-property
         },
         httpOptions: {
             connectTimeout: 60000, // https://github.com/aws/aws-sdk-js/pull/1446
@@ -146,7 +146,7 @@ function exists(apiConfig, backupFilePath, callback) {
     getS3Config(apiConfig, function (error, credentials) {
         if (error) return callback(error);
 
-        const s3 = new AWS.S3(credentials);
+        const s3 = new AWS.S3(_.omit(credentials, 'retryDelayOptions', 'maxRetries'));
 
         if (!backupFilePath.endsWith('/')) { // check for file
             const params = {