diff --git a/lib/filelib.php b/lib/filelib.php
index bc55e11c03b..e69825f47a7 100644
--- a/lib/filelib.php
+++ b/lib/filelib.php
@@ -2273,7 +2273,10 @@ function send_file($path, $filename, $lifetime = null , $filter=0, $pathisstring
 
     if ($forcedownload) {
         header('Content-Disposition: attachment; filename="'.$filename.'"');
-    } else {
+    } else if ($mimetype !== 'application/x-shockwave-flash') {
+        // If this is an swf don't pass content-disposition with filename as this makes the flash player treat the file
+        // as an upload and enforces security that may prevent the file from being loaded.
+
         header('Content-Disposition: inline; filename="'.$filename.'"');
     }