diff --git a/pkgs/applications/networking/browsers/firefox/update.nix b/pkgs/applications/networking/browsers/firefox/update.nix
index 596c2cb0a849..3dbd8f717414 100644
--- a/pkgs/applications/networking/browsers/firefox/update.nix
+++ b/pkgs/applications/networking/browsers/firefox/update.nix
@@ -43,7 +43,7 @@ writeScript "update-${attrPath}" ''
   #  - removes trailing slash
   #  - sorts everything with semver in mind
   #  - picks up latest release
-  version=`xidel -s $url --extract "//a" | \
+  version=`xidel --trace -s $url --extract "//a" | \
            grep "^${versionPrefix}[0-9.]*${versionSuffix}/$" | \
            sed s/[/]$// | \
            sort --version-sort | \