diff --git a/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php b/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
index addfc2e8fc..ccdd99586e 100644
--- a/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
+++ b/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
@@ -117,7 +117,7 @@ protected function getContentType(Request $request) {
       return $request->query->get('_format');
     }
 
-    if ($this->contentNegotiationConfig['respect_headers']['accept'] ?? FALSE) {
+    if ($this->contentNegotiationConfig['headers']['accept'] ?? FALSE) {
       $accept = AcceptHeader::fromString($request->headers->get('accept'));
       if (count($accept->all()) === 1 && $format = $request->getFormat($accept->first()->getValue())) {
         return $format;
diff --git a/sites/default/default.services.yml b/sites/default/default.services.yml
index baff7c5984..36e8f1782e 100644
--- a/sites/default/default.services.yml
+++ b/sites/default/default.services.yml
@@ -173,13 +173,14 @@ parameters:
     # Sets the Access-Control-Allow-Credentials header.
     supportsCredentials: false
 
-  # Configure HTTP content negotiation.
+  # Configure HTTP proactive content negotiation.
   # Read https://developer.mozilla.org/en-US/docs/Web/HTTP/Content_negotiation
   # for more information about the topic in general.
   content_negotiation.config:
-    # Specify the headers by which response can vary. At present, `accept` is
-    # the only supported header.
-    # Note: These settings will only be used if
-    # `use_http_content_negotiation_headers` is set to TRUE via settings.php
-    respect_headers:
-      - 'accept'
+    # Note: These settings will only be used if `enable_content_negotiation`
+    # is set to TRUE via settings.php. After Drupal 9.0, this configuration will
+    # be used regardless.
+    enabled: true
+    # Specify the headers by which responses may vary.
+    headers:
+      accept: true