diff --git a/guix/build/union.scm b/guix/build/union.scm
index 961ac3298b..bf75c67c52 100644
--- a/guix/build/union.scm
+++ b/guix/build/union.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2016, 2017, 2018, 2019, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2014 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2017 Huang Ying <huang.ying.caritas@gmail.com>
 ;;;
@@ -99,8 +99,9 @@ identical, #f otherwise."
   ;; a warning doesn't make sense.  For example, "icon-theme.cache" is
   ;; regenerated by a profile hook which shadows the file provided by
   ;; individual packages, and "gschemas.compiled" is made available to
-  ;; applications via 'glib-or-gtk-build-system'.
-  '("icon-theme.cache" "gschemas.compiled"))
+  ;; applications via 'glib-or-gtk-build-system'; "etc/ld.so.cache" is created
+  ;; for most packages.
+  '("icon-theme.cache" "gschemas.compiled" "ld.so.cache"))
 
 (define (warn-about-collision files)
   "Handle the collision among FILES by emitting a warning and choosing the