diff -u b/core/modules/media/media.install b/core/modules/media/media.install
--- b/core/modules/media/media.install
+++ b/core/modules/media/media.install
@@ -17,7 +17,9 @@
 
   $files = file_scan_directory($source, '/.*\.(svg|png|jpg|jpeg|gif)$/');
   foreach ($files as $file) {
-    file_unmanaged_copy($file->uri, $destination, FILE_EXISTS_REPLACE);
+    if (!file_exists($destination)) {
+      file_unmanaged_copy($file->uri, $destination, FILE_EXISTS_ERROR);
+    }
   }
 
   // Grant the "view media" permission to all users by default.