diff --git a/test/units/testsuite-64.sh b/test/units/testsuite-64.sh
index c4406f381b..9fe4e69928 100755
--- a/test/units/testsuite-64.sh
+++ b/test/units/testsuite-64.sh
@@ -89,6 +89,8 @@ check_device_unit() {(
     path="${2?}"
     unit=$(systemd-escape --path --suffix=device "$path")
 
+    [[ "$log_level" == 1 ]] && echo "INFO: check_device_unit($unit)"
+
     syspath=$(systemctl show --value --property SysFSPath "$unit" 2>/dev/null)
     if [[ -z "$syspath" ]]; then
         [[ "$log_level" == 1 ]] && echo >&2 "ERROR: $unit not found."
@@ -156,12 +158,11 @@ helper_check_device_units() {(
 
     local i
 
-    for ((i = 0; i < 20; i++)); do
-        (( i == 0 )) || sleep .5
-
+    for (( i = 0; i < 20; i++ )); do
         if check_device_units 0 "$@"; then
             return 0
         fi
+        sleep .5
     done
 
     check_device_units 1 "$@"
@@ -425,6 +426,26 @@ testcase_lvm_basic() {
     helper_check_device_symlinks "/dev/disk" "/dev/$vgroup"
     helper_check_device_units
 
+    # Mount mypart1 through by-label devlink
+    mkdir -p /tmp/mypart1-mount-point
+    mount /dev/disk/by-label/mylvpart1 /tmp/mypart1-mount-point
+    timeout 30 bash -c "while ! systemctl -q is-active /tmp/mypart1-mount-point; do sleep .2; done"
+    # Extend the partition and check if the device and mount units are still active.
+    # See https://bugzilla.redhat.com/show_bug.cgi?id=2158628
+    # Note, the test below may be unstable with LVM2 without the following patch:
+    # https://github.com/lvmteam/lvm2/pull/105
+    # But, to reproduce the issue, udevd must start to process the first 'change' uevent
+    # earlier than extending the volume has been finished, and in most case, the extension
+    # is hopefully fast.
+    lvm lvextend -y --size 8M "/dev/$vgroup/mypart1"
+    udevadm wait --settle --timeout="$timeout" "/dev/disk/by-label/mylvpart1"
+    timeout 30 bash -c "while ! systemctl -q is-active '/dev/$vgroup/mypart1'; do sleep .2; done"
+    timeout 30 bash -c "while ! systemctl -q is-active /tmp/mypart1-mount-point; do sleep .2; done"
+    # Umount the partition, otherwise the underlying device unit will stay in
+    # the inactive state and not be collected, and helper_check_device_units() will fail.
+    systemctl show /tmp/mypart1-mount-point
+    umount /tmp/mypart1-mount-point
+
     # Rename partitions (see issue #24518)
     lvm lvrename "/dev/$vgroup/mypart1" renamed1
     lvm lvrename "/dev/$vgroup/mypart2" renamed2