New Living Translation
Don’t let him find you sleeping when he arrives without warning.

American Standard Version
lest coming suddenly he find you sleeping.

Berean Study Bible
Otherwise, he may arrive without notice and find you sleeping.

Douay-Rheims Bible
Lest coming on a sudden, he find you sleeping.

English Revised Version
lest coming suddenly he find you sleeping.

King James Bible
Lest coming suddenly he find you sleeping.

World English Bible
lest coming suddenly he might find you sleeping.

Young's Literal Translation
lest, having come suddenly, he may find you sleeping;

Mark 13:36 Additional Translations ...