diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index c62c849..9ade5a5 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -12,8 +12,18 @@
{{ $css := resources.Get "css/main.css" }}
{{ if hugo.IsProduction }}
- {{ $css = $css | minify | fingerprint }}
-
+ {{ $cssFingerprinted := $css | minify | fingerprint }}
+
+ {{/* Also publish the same source at a second, stable, non-fingerprinted
+ URL — the fingerprinted one above changes hash on every deploy, so
+ it's unusable as a link target for an external same-origin
+ consumer (bookshop's pages, via BRAND_SITE_STYLESHEET_URL) that
+ can't track that hash. Referencing .RelPermalink is what makes
+ Hugo actually publish this resource; nothing else in this
+ template links it. Stray non-whitespace text directly in
+ gets moved into by the HTML parser, so this has to sit
+ inside a comment. */}}
+
{{ else }}
{{ end }}