diff --git a/repository/webdav/lib.php b/repository/webdav/lib.php
index 14d3bd3beaf..41da8fe89ac 100644
--- a/repository/webdav/lib.php
+++ b/repository/webdav/lib.php
@@ -72,7 +72,8 @@ class repository_webdav extends repository {
     }
     public function get_file($url, $title = '') {
         $url = urldecode($url);
-        $path = $this->prepare_file();
+        // Prepare a file with an arbitrary name - cannot be $title because of special chars (cf. MDL-57002).
+        $path = $this->prepare_file(uniqid());
         if (!$this->dav->open()) {
             return false;
         }