diff --git a/test/units/TEST-64-UDEV-STORAGE.sh b/test/units/TEST-64-UDEV-STORAGE.sh
index e868104d7b..69ca6e4d7a 100755
--- a/test/units/TEST-64-UDEV-STORAGE.sh
+++ b/test/units/TEST-64-UDEV-STORAGE.sh
@@ -1165,8 +1165,11 @@ uuid="deadbeef-dead-dead-beef-111111111111", name="mdpart1", size=8M
 uuid="deadbeef-dead-dead-beef-222222222222", name="mdpart2", size=32M
 uuid="deadbeef-dead-dead-beef-333333333333", name="mdpart3", size=16M
 EOF
+    udevadm wait --settle --timeout=30 "$raid_dev" "${raid_dev}1" "${raid_dev}2" "${raid_dev}3"
     # FIXME: For some reasons, the command sometimes stuck and the test will timeout.
     # Let's enable debug logging and set a timeout to make not consume CI resource.
+    # UPDATE: The above 'udevadm wait' command should fix the issue.
+    # But, let's keep the debug option for a while.
     SYSTEMD_LOG_LEVEL=debug timeout 30 udevadm trigger --settle --parent-match "$raid_dev"
     udevadm wait --settle --timeout=30 "/dev/disk/by-id/md-uuid-$uuid-part2"
     mkfs.ext4 -L "$part_name" "/dev/disk/by-id/md-uuid-$uuid-part2"