Konstantin Georgiev had been swapping over a trailer with co-worker Craig Stopforth when the tragedy happened.
The pair were changing trailers on January 11, 2019, on Common Lane in Fradley, Lichfield, when Mr Stopforth was killed.
Georgiev, of Stafford, failed to apply his handbrake correctly on his tractor unit and the parking brake on his trailer was also not set, said Staffordshire Police.
When connecting the air-hoses, the vehicle slowly rolled forward and crushed Mr Stopforth, of Telford, who was at the back of his trailer.
Mr Stopforth's trailer was parked in front and he was changing his registration plates over at the time.
Both men worked for a transport company in Telford at the time.
Georgiev, of Corran Road, pleaded guilty to causing death by careless driving and was sentenced at Stoke-on-Trent Crown Court today.
He was handed a six-month sentence suspended for two years.
Mr Stopforth's wife said in a statement: "It’s with the greatest regret and deepest sense of loss that I have had to say goodbye to my husband, needlessly killed in January 2019.
"I miss every atom of him. His big laugh, huge hugs and wicked sense of humour. To say I love and miss him endlessly just isn’t enough. The effect his death has had on myself and our family is overwhelming."
Sergeant Richard Moors, from the Staffordshire and West Midlands Serious Collision Investigation Unit, said after the hearing: "This was a tragic event.
"I would urge drivers of any vehicle, not just lorries, to ensure their own and others safety and check that the handbrake is correctly engaged before exiting their vehicle.
"A family have been left devastated by the actions of Georgiev that night in, what was, an easily avoidable incident."