diff --git a/README.md b/README.md
index b6ca101..42c148e 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ $schemes = [
       // Optional configuration settings.
 
       // 'options' => [
-      //   'ACL' => 'public-read',
+      //   'ACL' => 'public-read',   // If bucket is private, set to 'private'
       //   'StorageClass' => 'REDUCED_REDUNDANCY',
       // ],
 
@@ -59,9 +59,11 @@ $schemes = [
 
       // 'endpoint' => 'https://api.example.com', // An alternative API endpoint
                                                   // for 3rd party S3 providers.
-      // 'expires' => '+600 seconds',             // If a file is private, the
-                                                  // expiry time of a presigned
-                                                  // URL.
+      // 'expires' => '+600 seconds',             // An optional expiry time
+                                                  // to use when generating
+                                                  // presigend URLs for private
+                                                  // files. Default is +3600
+                                                  // seconds (one hour).
     ],
 
     'cache' => TRUE, // Creates a metadata cache to speed up lookups.
diff --git a/src/Flysystem/S3.php b/src/Flysystem/S3.php
index 13d7ce8..3a530b2 100644
--- a/src/Flysystem/S3.php
+++ b/src/Flysystem/S3.php
@@ -114,7 +114,7 @@ class S3 implements FlysystemPluginInterface, ContainerFactoryPluginInterface {
     $this->bucket = $config->get('bucket', '');
     $this->prefix = $config->get('prefix', '');
     $this->options = $config->get('options', []);
-    $this->expires = $config->get('expires');
+    $this->expires = $config->get('expires', '+3600 seconds');
 
     $this->urlPrefix = $this->calculateUrlPrefix($config);
 
@@ -216,7 +216,7 @@ class S3 implements FlysystemPluginInterface, ContainerFactoryPluginInterface {
     // we log it and return an unsigned URL so we don't break the expected
     // return or completely break the response.
     try {
-      if ($this->options['ACL'] != 'public-read' && $this->getAdapter()->getVisibility($target)['visibility'] == AdapterInterface::VISIBILITY_PRIVATE && $this->expires) {
+      if ($this->options['ACL'] != 'public-read' && $this->getAdapter()->getVisibility($target)['visibility'] == AdapterInterface::VISIBILITY_PRIVATE) {
         // Use getCommand() so we don't actually make a request yet.
         $command = $this->client->getCommand('getObject', [
           'Bucket' => $this->bucket,