diff --git a/gnu/packages/backup.scm b/gnu/packages/backup.scm
index 1e9298f68c..a92c8c9aca 100644
--- a/gnu/packages/backup.scm
+++ b/gnu/packages/backup.scm
@@ -258,7 +258,9 @@ backups (called chunks) to allow easy burning to CD/DVD.")
                     (zlib    (assoc-ref inputs "zlib"))
                     (zstd    (assoc-ref inputs "zstd"))
                     (bzip2   (assoc-ref inputs "bzip2")))
-               (substitute* (string-append lib "/pkgconfig/libarchive.pc")
+               ;; Embed absolute references to these inputs to avoid propagation.
+               (substitute* (list (string-append lib "/pkgconfig/libarchive.pc")
+                                  (string-append lib "/libarchive.la"))
                  (("-lnettle")
                   (string-append "-L" nettle "/lib -lnettle"))
                  (("-lxml2")