diff --git a/gnu/packages/mes.scm b/gnu/packages/mes.scm
index 412930faed..289232990d 100644
--- a/gnu/packages/mes.scm
+++ b/gnu/packages/mes.scm
@@ -203,83 +203,6 @@ (define-public mes
     (home-page "https://www.gnu.org/software/mes/")
     (license gpl3+)))
 
-(define-public mes-rb5
-  ;; This is the Reproducible-Builds summit 5's Mes, also built on Debian
-  ;; GNU/Linux and NixOS to produce the same, bit-for-bit identical result.
-  (package
-    (inherit mes)
-    (name "mes-rb5")
-    (version "0.22")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "mirror://gnu/mes/"
-                                  "mes-" version ".tar.gz"))
-              (sha256
-               (base32
-                "0p1jsrrmcbc0zrvbvnjbb6iyxr0in71km293q8qj6gnar6bw09av"))))
-    (supported-systems '("i686-linux" "x86_64-linux"))
-    (inputs '())
-    (propagated-inputs '())
-    (native-inputs
-     `(("bash" ,bash)
-       ("coreutils" ,coreutils)
-       ("grep" ,grep)
-       ("guile" ,guile-2.2)
-       ("gzip" ,gzip)
-       ("libc" ,glibc)
-       ("locales" ,glibc-utf8-locales)
-       ("make" ,gnu-make)
-       ("mes" ,mes)
-       ("mescc-tools" ,mescc-tools)
-       ("nyacc" ,nyacc-0.99)
-       ("sed" ,sed)
-       ("tar" ,tar)))
-    (supported-systems '("i686-linux"))
-    (arguments
-     `(#:implicit-inputs? #f
-       #:strip-binaries? #f    ; binutil's strip b0rkes MesCC/M1/hex2 binaries
-       #:modules ((guix build gnu-build-system)
-                  (guix build utils)
-                  (ice-9 popen)
-                  (ice-9 rdelim))
-       #:phases
-       (modify-phases %standard-phases
-         (add-before 'configure 'setenv
-           (lambda _
-             (setenv "AR" "mesar")
-             (setenv "CC" "mescc")
-             (setenv "GUILD" "true")
-             (setenv "SCHEME" "mes")
-             (setenv "LC_ALL" "en_US.UTF-8")
-             #t))
-         (replace 'configure
-           (lambda _
-             (let ((out (assoc-ref %outputs "out")))
-               (invoke "sh" "configure.sh"
-                       (string-append "--prefix=" out)
-                       "--host=i686-unkown-linux-gnu"
-                       "--with-courage"))))
-         (replace 'build
-           (lambda _
-             (invoke "sh" "bootstrap.sh")))
-         (replace 'check
-           (lambda _
-             (copy-file "bin/mes-mescc" "bin/mes-mescc-0.21")
-             (system* "sed" "-i" "s/0\\.22/0\\.21/" "bin/mes-mescc-0.21")
-             (let ((sha256sum
-                    (read-delimited
-                     " "
-                     (open-pipe* OPEN_READ "sha256sum" "bin/mes-mescc-0.21"))))
-               (unless
-                   (equal?
-                    sha256sum
-                    "9e0bcb1633c58e7bc415f6ea27cee7951d6b0658e13cdc147e992b31a14625fb")
-                 (throw 'error "mes checksum failure"))
-               #t)))
-         (replace 'install
-           (lambda _
-             (invoke "sh" "install.sh"))))))))
-
 (define-public mescc-tools
   (package
     (name "mescc-tools")