diff --git a/contrib/guix/libexec/build.sh b/contrib/guix/libexec/build.sh
index 556df1a..5875cf5 100755
--- a/contrib/guix/libexec/build.sh
+++ b/contrib/guix/libexec/build.sh
@@ -58,7 +58,8 @@ BASEPREFIX="${PWD}/contrib/depends"
 store_path() {
     grep --extended-regexp "/[^-]{32}-${1}-[^-]+${2:+-${2}}" "${GUIX_ENVIRONMENT}/manifest" \
         | head --lines=1 \
-        | sed --expression='s|^[[:space:]]*"||' \
+        | sed --expression='s|\x29*$||' \
+              --expression='s|^[[:space:]]*"||' \
               --expression='s|"[[:space:]]*$||'
 }
 
diff --git a/contrib/guix/libexec/prelude.bash b/contrib/guix/libexec/prelude.bash
index 9575edb..063f65c 100644
--- a/contrib/guix/libexec/prelude.bash
+++ b/contrib/guix/libexec/prelude.bash
@@ -51,7 +51,7 @@ fi
 time-machine() {
     # shellcheck disable=SC2086
     guix time-machine --url=https://git.savannah.gnu.org/git/guix.git \
-                      --commit=998eda3067c7d21e0d9bb3310d2f5a14b8f1c681 \
+                      --commit=160f78a4d92205df986ed9efcce7d3aac188cb24 \
                       --cores="$JOBS" \
                       --keep-failed \
                       --fallback \