diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 29e5c3aa3a645a016b0cba274729a5226802d16b..22a2e97f8178f9ee7fa6a5247b23179eb8428268 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -2561,7 +2561,6 @@ function get_t() {
  * Initialize all the defined language types.
  */
 function drupal_language_initialize() {
-  global $language;
   $types = language_types();
 
   // Ensure the language is correctly returned, even without multilanguage
@@ -2581,9 +2580,6 @@ function drupal_language_initialize() {
     // environments.
     bootstrap_invoke_all('language_init');
   }
-
-  // Send appropriate HTTP-Header for browsers and search engines.
-  header('Content-Language: ' . $language->language);
 }
 
 /**
diff --git a/includes/common.inc b/includes/common.inc
index c851715022cec25b60ddf8d4dd930d48ce24040e..9b0a73748bb93b38284650ee00d381c2eb17af63 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2467,6 +2467,10 @@ function drupal_deliver_html_page($page_callback_result) {
     drupal_add_http_header('Content-Type', 'text/html; charset=utf-8');
   }
 
+  // Send appropriate HTTP-Header for browsers and search engines.
+  global $language;
+  drupal_add_http_header('Content-Language', $language->language);
+
   // Menu status constants are integers; page content is a string or array.
   if (is_int($page_callback_result)) {
     // @todo: Break these up into separate functions?