diff --git a/lib/csslib.php b/lib/csslib.php
index 5fc0f9b16ab..2fdbb7357a8 100644
--- a/lib/csslib.php
+++ b/lib/csslib.php
@@ -99,7 +99,7 @@ function css_send_ie_css($themename, $rev) {
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     header('Pragma: ');
-    header('Cache-Control: max-age='.$lifetime);
+    header('Cache-Control: public, max-age='.$lifetime);
     header('Accept-Ranges: none');
     header('Content-Type: text/css; charset=utf-8');
     header('Content-Length: '.strlen($css));
@@ -124,7 +124,7 @@ function css_send_cached_css($csspath, $rev) {
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($csspath)) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     header('Pragma: ');
-    header('Cache-Control: max-age='.$lifetime);
+    header('Cache-Control: public, max-age='.$lifetime);
     header('Accept-Ranges: none');
     header('Content-Type: text/css; charset=utf-8');
     if (!min_enable_zlib_compression()) {
diff --git a/theme/image.php b/theme/image.php
index b76bd26c4e6..d13aabbb2e6 100644
--- a/theme/image.php
+++ b/theme/image.php
@@ -82,7 +82,7 @@ if ($rev > -1) {
             $mimetype = get_contenttype_from_ext($ext);
             header('HTTP/1.1 304 Not Modified');
             header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
-            header('Cache-Control: max-age='.$lifetime);
+            header('Cache-Control: public, max-age='.$lifetime);
             header('Content-Type: '.$mimetype);
             die;
         }
@@ -153,7 +153,7 @@ function send_cached_image($imagepath, $rev) {
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', time()) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     header('Pragma: ');
-    header('Cache-Control: max-age='.$lifetime);
+    header('Cache-Control: public, max-age='.$lifetime);
     header('Accept-Ranges: none');
     header('Content-Type: '.$mimetype);
     header('Content-Length: '.filesize($imagepath));
diff --git a/theme/javascript.php b/theme/javascript.php
index 4151172a711..cfc1eb04877 100644
--- a/theme/javascript.php
+++ b/theme/javascript.php
@@ -59,7 +59,7 @@ if ($rev > -1 and file_exists($candidate)) {
         $lifetime = 60*60*24*30; // 30 days
         header('HTTP/1.1 304 Not Modified');
         header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
-        header('Cache-Control: max-age='.$lifetime);
+        header('Cache-Control: public, max-age='.$lifetime);
         header('Content-Type: application/javascript; charset=utf-8');
         die;
     }
@@ -108,7 +108,7 @@ function send_cached_js($jspath) {
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($jspath)) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     header('Pragma: ');
-    header('Cache-Control: max-age='.$lifetime);
+    header('Cache-Control: public, max-age='.$lifetime);
     header('Accept-Ranges: none');
     header('Content-Type: application/javascript; charset=utf-8');
 
diff --git a/theme/styles.php b/theme/styles.php
index 5f6fd90ee68..07bb0a0edd5 100644
--- a/theme/styles.php
+++ b/theme/styles.php
@@ -64,7 +64,7 @@ if (file_exists($candidatesheet)) {
         $lifetime = 60*60*24*30; // 30 days
         header('HTTP/1.1 304 Not Modified');
         header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
-        header('Cache-Control: max-age='.$lifetime);
+        header('Cache-Control: public, max-age='.$lifetime);
         header('Content-Type: text/css; charset=utf-8');
         die;
     }
diff --git a/theme/yui_combo.php b/theme/yui_combo.php
index 8683cd6953d..e68d1c19600 100644
--- a/theme/yui_combo.php
+++ b/theme/yui_combo.php
@@ -56,7 +56,7 @@ if (strpos($parts, '/-1/') === false and (!empty($_SERVER['HTTP_IF_NONE_MATCH'])
     $lifetime = 60*60*24*30; // 30 days
     header('HTTP/1.1 304 Not Modified');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
-    header('Cache-Control: max-age='.$lifetime);
+    header('Cache-Control: public, max-age='.$lifetime);
     header('Content-Type: '.$mimetype);
     die;
 }
diff --git a/theme/yui_image.php b/theme/yui_image.php
index 1c2012e1d39..b6555db5545 100644
--- a/theme/yui_image.php
+++ b/theme/yui_image.php
@@ -90,7 +90,7 @@ function yui_image_cached($imagepath) {
     header('Last-Modified: '. gmdate('D, d M Y H:i:s', filemtime($imagepath)) .' GMT');
     header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
     header('Pragma: ');
-    header('Cache-Control: max-age=315360000');
+    header('Cache-Control: public, max-age=315360000');
     header('Accept-Ranges: none');
     header('Content-Type: '.$mimetype);
     header('Content-Length: '.filesize($imagepath));