diff --git a/tests/kolainst/destructive/auto-prune.sh b/tests/kolainst/destructive/auto-prune.sh
index 5081275e07..707b5fd30e 100755
--- a/tests/kolainst/destructive/auto-prune.sh
+++ b/tests/kolainst/destructive/auto-prune.sh
@@ -5,6 +5,47 @@ set -xeuo pipefail
 
 . ${KOLA_EXT_DATA}/libinsttest.sh
 
+journal_cursor() {
+    journalctl -o json -n 1 | jq -r '.["__CURSOR"]'
+}
+
+assert_journal_grep() {
+    local cursor re
+    cursor=$1
+    shift
+    re=$1
+    shift
+
+    if ! journalctl -u ostree-finalize-staged --after-cursor "${cursor}" --grep="$re" "$@" >/dev/null; then
+        fatal "failed to find in journal: $re"; exit 1
+    fi
+}
+
+assert_not_journal_grep() {
+    local cursor re
+    cursor=$1
+    shift
+    re=$1
+    shift
+
+    if journalctl -u ostree-finalize-staged --after-cursor "${cursor}" --grep="$re" "$@"; then
+        fatal "found in journal: $re"; exit 1
+    fi
+}
+
+inject_no_early_prune() {
+    mkdir -p /run/systemd/system/ostree-finalize-staged.service.d
+    cat >/run/systemd/system/ostree-finalize-staged.service.d/10-no-early-prune.conf << 'EOF'
+[Service]
+Environment=OSTREE_SYSROOT_OPTS=no-early-prune
+EOF
+    systemctl daemon-reload
+}
+
+remove_no_early_prune() {
+    rm -vf /run/systemd/system/ostree-finalize-staged.service.d/10-no-early-prune.conf
+}
+
 # make two fake ostree commits with modified kernels of about the same size
 cd /root
 mkdir -p rootfs/usr/lib/modules/`uname -r`
@@ -44,12 +85,12 @@ assert_bootfs_has_n_bootcsum_dirs 1
 # the booted deployment is never pruned, so this is a hopeless case and auto-pruning can't save us
 consume_bootfs_space
 rpm-ostree rebase :modkernel1
-if ostree admin finalize-staged |& tee out.txt; then
+cursor=$(journal_cursor)
+if systemctl restart ostree-finalize-staged; then
     assert_not_reached "successfully wrote to filled up bootfs"
 fi
-assert_file_has_content out.txt "Disabling auto-prune optimization; insufficient space left in bootfs"
-assert_file_has_content out.txt "No space left on device"
-rm out.txt
+assert_journal_grep "${cursor}" "No space left on device"
+assert_journal_grep "${cursor}" "Disabling auto-prune optimization.*insufficient space"
 unconsume_bootfs_space
 rpm-ostree cleanup -bpr
 
@@ -58,9 +99,9 @@ rpm-ostree cleanup -bpr
 assert_bootfs_has_n_bootcsum_dirs 1
 
 rpm-ostree rebase :modkernel1
-ostree admin finalize-staged |& tee out.txt
-assert_not_file_has_content out.txt "updating bootloader in two steps"
-rm out.txt
+cursor=$(journal_cursor)
+systemctl restart ostree-finalize-staged
+assert_not_journal_grep "$cursor" "updating bootloader in two steps"
 
 # and put it in rollback position; this is the deployment that'll get auto-pruned
 rpm-ostree rollback
@@ -71,11 +112,13 @@ bootloader_orig=$(sha256sum /boot/loader/entries/*)
 # now try to deploy a third deployment without early pruning; we should hit ENOSPC
 consume_bootfs_space
 rpm-ostree rebase :modkernel2
-if OSTREE_SYSROOT_OPTS=no-early-prune ostree admin finalize-staged |& tee out.txt; then
+inject_no_early_prune
+cursor=$(journal_cursor)
+if systemctl restart ostree-finalize-staged; then
     assert_not_reached "successfully wrote kernel without auto-pruning"
 fi
-assert_file_has_content out.txt "No space left on device"
-rm out.txt
+assert_journal_grep "No space left on device"
+remove_no_early_prune
 
 # there's 3 bootcsums now because it'll also have the partially written
 # bootcsum dir we were creating when we hit ENOSPC; this verifies that all the
@@ -86,9 +129,9 @@ assert_streq "$bootloader_orig" "$(sha256sum /boot/loader/entries/*)"
 
 # now, try again but with auto-pruning enabled
 rpm-ostree rebase :modkernel2
-ostree admin finalize-staged |& tee out.txt
-assert_file_has_content out.txt "updating bootloader in two steps"
-rm out.txt
+cursor=$(journal_cursor)
+systemctl restart ostree-finalize-staged
+assert_not_journal_grep "$cursor" "updating bootloader in two steps"
 
 assert_bootfs_has_n_bootcsum_dirs 2
 assert_not_streq "$bootloader_orig" "$(sha256sum /boot/loader/entries/*)"
@@ -122,17 +165,19 @@ consume_bootfs_space "$((free_blocks_kernel_and_initrd))"
 
 rpm-ostree rebase :modkernel1
 # Disable auto-pruning to verify we reproduce the bug
-if OSTREE_SYSROOT_OPTS=no-early-prune ostree admin finalize-staged |& tee out.txt; then
+inject_no_early_prune
+cursor=$(journal_cursor)
+if systemctl restart ostree-finalize-staged; then
     assert_not_reached "successfully wrote kernel without auto-pruning"
 fi
-assert_file_has_content out.txt "No space left on device"
-rm out.txt
+assert_journal_grep "No space left on device"
+remove_no_early_prune
 
 # now, try again but with (now default) auto-pruning enabled
 rpm-ostree rebase :modkernel1
-ostree admin finalize-staged |& tee out.txt
-assert_file_has_content out.txt "updating bootloader in two steps"
-rm out.txt
+cursor=$(journal_cursor)
+systemctl restart ostree-finalize-staged
+assert_journal_grep "$cursor" "updating bootloader in two steps"
 
 # Below, we test that the size estimator is blocksize aware. This catches the
 # case where the dtb contains many small files such that there's a lot of wasted
@@ -150,16 +195,18 @@ consume_bootfs_space "$((free_blocks_kernel_and_initrd - 10000))"
 
 rpm-ostree rebase :modkernel3
 # Disable auto-pruning to verify we reproduce the bug
-if OSTREE_SYSROOT_OPTS=no-early-prune ostree admin finalize-staged |& tee out.txt; then
+inject_no_early_prune
+cursor=$(journal_cursor)
+if systemctl restart ostree-finalize-staged; then
     assert_not_reached "successfully wrote kernel without auto-pruning"
 fi
-assert_file_has_content out.txt "No space left on device"
-rm out.txt
+assert_journal_grep "No space left on device"
+remove_no_early_prune
 
 # now, try again but with (now default) auto-pruning enabled
 rpm-ostree rebase :modkernel3
-ostree admin finalize-staged |& tee out.txt
-assert_file_has_content out.txt "updating bootloader in two steps"
-rm out.txt
+cursor=$(journal_cursor)
+systemctl restart ostree-finalize-staged
+assert_journal_grep "$cursor" "updating bootloader in two steps"
 
 echo "ok bootfs auto-prune"