diff --git a/config.js b/config.js
index de014b6..16eb8b7 100644
--- a/config.js
+++ b/config.js
@@ -136,7 +136,7 @@ config.s3ForcePathStyle = argv.s3_force_path_style || fromConfigFile("s3ForcePat
 config.s3AccessKey = argv.s3_access_key || fromConfigFile("s3AccessKey", process.env.AWS_ACCESS_KEY_ID || "")
 config.s3SecretKey = argv.s3_secret_key || fromConfigFile("s3SecretKey", process.env.AWS_SECRET_ACCESS_KEY || "")
 config.s3SignatureVersion = argv.s3_signature_version || fromConfigFile("s3SignatureVersion", "4")
-config.s3ACL = argv.s3_acl || fromConfigFile("s3_acl", "public-read")
+config.s3ACL = argv.s3_acl || fromConfigFile("s3_acl", "");
 config.s3UploadEverything = argv.s3_upload_everything || fromConfigFile("s3UploadEverything", false);
 config.maxConcurrency = parseInt(argv.max_concurrency || fromConfigFile("maxConcurrency", 0));
 config.maxRuntime = parseInt(argv.max_runtime || fromConfigFile("maxRuntime", -1));
diff --git a/libs/S3.js b/libs/S3.js
index 5672e53..ec91979 100644
--- a/libs/S3.js
+++ b/libs/S3.js
@@ -106,13 +106,15 @@ module.exports = {
                 logger.debug(`Uploading ${file.src} --> ${file.dest}`);
                 const filename = path.basename(file.dest);
                 progress[filename] = 0;
-
-                s3.upload({
+                
+                const uploadOpts = {
                     Bucket: bucket,
                     Key: file.dest,
-                    Body: fs.createReadStream(file.src),
-                    ACL: config.s3ACL
-                }, {partSize, queueSize: concurrency}, err => {
+                    Body: fs.createReadStream(file.src)
+                };
+                if (config.s3ACL) uploadOpts.ACL = config.s3ACL;
+                
+                s3.upload(uploadOpts, {partSize, queueSize: concurrency}, err => {
                     if (err){
                         logger.debug(err);
                         const msg = `Cannot upload file to S3: ${err.code}, retrying... ${file.retries}`;