diff --git a/src/IDF/Form/Upload.php b/src/IDF/Form/Upload.php
index a88c2c3..f308142 100644
--- a/src/IDF/Form/Upload.php
+++ b/src/IDF/Form/Upload.php
@@ -49,7 +49,8 @@ class IDF_Form_Upload extends Pluf_Form
                                             'label' => __('File'),
                                             'initial' => '',
                                             'move_function_params' => array('upload_path' => Pluf::f('upload_path').'/'.$this->project->shortname.'/files',
-                                                                            'upload_path_create' => true),
+                                                                            'upload_path_create' => true,
+                                                                            'upload_overwrite' => false),
 
                                             ));
         for ($i=1;$i<7;$i++) {
@@ -70,9 +71,6 @@ class IDF_Form_Upload extends Pluf_Form
         if (!preg_match('/\.(png|jpg|jpeg|gif|bmp|psd|tif|aiff|asf|avi|bz2|css|doc|eps|gz|mdtext|mid|mov|mp3|mpg|ogg|pdf|ppt|ps|qt|ra|ram|rm|rtf|sdd|sdw|sit|sxi|sxw|swf|tgz|txt|wav|xls|xml|wmv|zip)$/i', $this->cleaned_data['file'])) {
             throw new Pluf_Form_Invalid(__('For security reason, you cannot upload a file with this extension.'));
         }
-        if (file_exists(Pluf::f('upload_path').'/'.$this->project->shortname.'/files/'.$this->cleaned_data['file'])) {
-            throw new Pluf_Form_Invalid(sprintf(__('A file with the name "%s" is already available for download.'), $this->cleaned_data['file']));
-        }
         return $this->cleaned_data['file'];
     }