diff --git a/htdocs/core/actions_linkedfiles.inc.php b/htdocs/core/actions_linkedfiles.inc.php
index f8ac8ab0be0..2542cf23268 100644
--- a/htdocs/core/actions_linkedfiles.inc.php
+++ b/htdocs/core/actions_linkedfiles.inc.php
@@ -52,15 +52,16 @@ if (GETPOST('sendit', 'alpha') && !empty($conf->global->MAIN_UPLOAD_DOC))
 		{
 			// Define if we have to generate thumbs or not
 			$generatethumbs = 1;
-			if (GETPOST('section_dir')) $generatethumbs = 0;
+			if (GETPOST('section_dir', 'alpha')) $generatethumbs = 0;
+			$allowoverwrite = (GETPOST('overwritefile', 'int') ? 1 : 0);
 
 			if (!empty($upload_dirold) && !empty($conf->global->PRODUCT_USE_OLD_PATH_FOR_PHOTO))
 			{
-				$result = dol_add_file_process($upload_dirold, 0, 1, 'userfile', GETPOST('savingdocmask', 'alpha'), null, '', $generatethumbs);
+				$result = dol_add_file_process($upload_dirold, $allowoverwrite, 1, 'userfile', GETPOST('savingdocmask', 'alpha'), null, '', $generatethumbs);
 			}
 			elseif (!empty($upload_dir))
 			{
-				$result = dol_add_file_process($upload_dir, 0, 1, 'userfile', GETPOST('savingdocmask', 'alpha'), null, '', $generatethumbs);
+				$result = dol_add_file_process($upload_dir, $allowoverwrite, 1, 'userfile', GETPOST('savingdocmask', 'alpha'), null, '', $generatethumbs);
 			}
 		}
 	}
diff --git a/htdocs/core/class/html.formfile.class.php b/htdocs/core/class/html.formfile.class.php
index 52e852188d6..4a50525c88a 100644
--- a/htdocs/core/class/html.formfile.class.php
+++ b/htdocs/core/class/html.formfile.class.php
@@ -76,7 +76,7 @@ class FormFile
 	 *  @param	integer		$linkfiles		1=Also add form to link files, 0=Do not show form to link files
 	 *  @param	string		$htmlname		Name and id of HTML form ('formuserfile' by default, 'formuserfileecm' when used to upload a file in ECM)
 	 *  @param	string		$accept			Specifies the types of files accepted (This is not a security check but an user interface facility. eg '.pdf,image/*' or '.png,.jpg' or 'video/*')
-	 *	@param	string		$sectiondir		If upload must be done inside a particular directory (is sectiondir defined, sectionid must not be)
+	 *	@param	string		$sectiondir		If upload must be done inside a particular directory (if sectiondir defined, sectionid must not be)
 	 *  @param  int         $usewithoutform 0=Default, 1=Disable <form> and style to use in existing area
 	 * 	@return	int							<0 if KO, >0 if OK
 	 */
@@ -108,8 +108,6 @@ class FormFile
 				return 1;
 			}
 
-			$maxlength = $size;
-
 			$out = "\n\n".'<!-- Start form attach new file --><div class="formattachnewfile">'."\n";
 
 			if (empty($title)) $title = $langs->trans("AttachANewFile");
@@ -174,6 +172,10 @@ class FormFile
 			$out .= (!empty($accept) ? ' accept="'.$accept.'"' : ' accept=""');
 			$out .= '>';
 			$out .= ' ';
+			if ($sectionid) {	// Show overwrite if exists for ECM module only
+				$langs->load('link');
+				$out .= '<input style="margin-right: 2px;" type="checkbox" id="overwritefile" name="overwritefile" value="1"><label for="overwritefile">'.$langs->trans("OverwriteIfExists").'</label>';
+			}
 			$out .= '<input type="submit" class="button reposition" name="sendit" value="'.$langs->trans("Upload").'"';
 			$out .= (empty($conf->global->MAIN_UPLOAD_DOC) || empty($perm) ? ' disabled' : '');
 			$out .= '>';
diff --git a/htdocs/core/lib/files.lib.php b/htdocs/core/lib/files.lib.php
index a39e48e3a60..9746c1047b8 100644
--- a/htdocs/core/lib/files.lib.php
+++ b/htdocs/core/lib/files.lib.php
@@ -1598,13 +1598,18 @@ function dol_add_file_process($upload_dir, $allowoverwrite = 0, $donotupdatesess
 						$formmail->add_attached_files($destfull, $destfile, $TFile['type'][$i]);
 					}
 
-					// Update table of files
+					// Update index table of files (llx_ecm_files)
 					if ($donotupdatesession == 1)
 					{
 						$result = addFileIntoDatabaseIndex($upload_dir, basename($destfile), $TFile['name'][$i], 'uploaded', 0);
 						if ($result < 0)
 						{
-							setEventMessages('FailedToAddFileIntoDatabaseIndex', '', 'warnings');
+							if ($allowoverwrite) {
+								// Do not show error message. We can have an error due to DB_ERROR_RECORD_ALREADY_EXISTS
+							}
+							else {
+								setEventMessages('FailedToAddFileIntoDatabaseIndex', '', 'warnings');
+							}
 						}
 					}
 
@@ -1760,7 +1765,6 @@ function addFileIntoDatabaseIndex($dir, $file, $fullpathorig = '', $mode = 'uplo
 	return $result;
 }
 
-
 /**
  *  Delete files into database index using search criterias.
  *
diff --git a/htdocs/langs/en_US/link.lang b/htdocs/langs/en_US/link.lang
index fdcf07aeff4..1ffcd41a18b 100644
--- a/htdocs/langs/en_US/link.lang
+++ b/htdocs/langs/en_US/link.lang
@@ -8,3 +8,4 @@ LinkRemoved=The link %s has been removed
 ErrorFailedToDeleteLink= Failed to remove link '<b>%s</b>'
 ErrorFailedToUpdateLink= Failed to update link '<b>%s</b>'
 URLToLink=URL to link
+OverwriteIfExists=Overwrite file if exists