diff --git a/contrib/guix/guix-build.sh b/contrib/guix/guix-build.sh
index c39e9fe9b20..7c32fb57265 100755
--- a/contrib/guix/guix-build.sh
+++ b/contrib/guix/guix-build.sh
@@ -163,7 +163,7 @@ SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:-$(git log --format=%at -1)}"
 time-machine() {
     # shellcheck disable=SC2086
     guix time-machine --url=https://github.com/dongcarl/guix.git \
-                      --commit=6c9d16db962a6f7155571b36eced681fd2889e23 \
+                      --commit=490e39ff303f4f6873a04bfb8253755bdae1b29c \
                       --max-jobs="$MAX_JOBS" \
                       --keep-failed \
                       ${SUBSTITUTE_URLS:+--substitute-urls="$SUBSTITUTE_URLS"} \
diff --git a/contrib/guix/manifest.scm b/contrib/guix/manifest.scm
index fb585b7f253..e0e2e1e16ed 100644
--- a/contrib/guix/manifest.scm
+++ b/contrib/guix/manifest.scm
@@ -125,9 +125,9 @@ chain for " target " development."))
 
 (define* (make-bitcoin-cross-toolchain target
                                   #:key
-                                  (base-gcc-for-libc gcc-5)
-                                  (base-kernel-headers linux-libre-headers-4.19)
-                                  (base-libc glibc-2.27)
+                                  (base-gcc-for-libc gcc-7)
+                                  (base-kernel-headers linux-libre-headers-5.4)
+                                  (base-libc glibc)  ; glibc 2.31
                                   (base-gcc (make-gcc-rpath-link gcc-9)))
   "Convenience wrapper around MAKE-CROSS-TOOLCHAIN with default values
 desirable for building Bitcoin Core release binaries."
@@ -232,12 +232,6 @@ chain for " target " development."))
            (list zip
                  (make-mingw-pthreads-cross-toolchain "x86_64-w64-mingw32")
                  (make-nsis-with-sde-support nsis-x86_64)))
-          ((string-contains target "riscv64-linux-")
-           (list (make-bitcoin-cross-toolchain target
-                                               #:base-gcc-for-libc gcc-7)))
-          ((string-contains target "powerpc64le-linux-")
-           (list (make-bitcoin-cross-toolchain target
-                                               #:base-gcc-for-libc gcc-7)))
           ((string-contains target "-linux-")
            (list (make-bitcoin-cross-toolchain target)))
           ((string-contains target "darwin")