diff --git a/test/units/testsuite-81.fstab-generator.sh b/test/units/testsuite-81.fstab-generator.sh
index 4a69245ed87..e50419a0ecc 100755
--- a/test/units/testsuite-81.fstab-generator.sh
+++ b/test/units/testsuite-81.fstab-generator.sh
@@ -13,6 +13,7 @@ OUT_DIR="$(mktemp -d /tmp/fstab-generator.XXX)"
 FSTAB="$(mktemp)"
 
 at_exit() {
+    mountpoint -q /proc/cmdline && umount /proc/cmdline
     rm -fr "${OUT_DIR:?}" "${FSTAB:?}"
 }
 
@@ -294,6 +295,12 @@ check_fstab_mount_units() {
     done
 }
 
+# Drop usrhash on the command-line so fstab-generator doesn't add a /dev/mapper
+# mount for /usr, add a root= to emulate a more typical environment,
+# and remove any systemd.mount-extra=
+sed -r -e 's/usrhash=[^[:space:]+]/root=\/dev\/sda2/' -e 's/systemd.mount-extra=[^[:space:]+]//g' /proc/cmdline >/tmp/cmdline.tmp
+mount --bind /tmp/cmdline.tmp /proc/cmdline
+
 : "fstab-generator: regular"
 printf "%s\n" "${FSTAB_GENERAL_ROOT[@]}" >"$FSTAB"
 cat "$FSTAB"