diff --git a/src/EventSubscriber/AddSoftPurgeHeaders.php b/src/EventSubscriber/AddSoftPurgeHeaders.php
index 2900bf5..810e0d8 100644
--- a/src/EventSubscriber/AddSoftPurgeHeaders.php
+++ b/src/EventSubscriber/AddSoftPurgeHeaders.php
@@ -45,7 +45,7 @@ class AddSoftPurgeHeaders implements EventSubscriberInterface {
   }
 
   /**
-   * Adds Cache-Control headers if soft purging is enabled.
+   * Adds Surrogate-Control header if soft purging is enabled.
    *
    * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
    *   The event to process.
@@ -62,16 +62,16 @@ class AddSoftPurgeHeaders implements EventSubscriberInterface {
     // Get response.
     $response = $event->getResponse();
 
-    // Build the modified Cache-Control header.
+    // Build the Surrogate-Control header.
     $cache_control_header = $response->headers->get('Cache-Control');
-    $cache_control_header .= ', stale-while-revalidate=' . $config->get('stale_while_revalidate_value');
+    $surrogate_control_header = $cache_control_header . ', stale-while-revalidate=' . $config->get('stale_while_revalidate_value');
 
     if ((bool) $config->get('stale_if_error')) {
-      $cache_control_header .= ', stale-if-error=' . $config->get('stale_if_error_value');
+      $surrogate_control_header .= ', stale-if-error=' . $config->get('stale_if_error_value');
     }
 
     // Set the modified Cache-Control header.
-    $response->headers->set('Cache-Control', $cache_control_header);
+    $response->headers->set('Surrogate-Control', $surrogate_control_header);
   }
 
   /**