Sheehan, 30, will remain at the club until the end of the 2027‑28 campaign. The former Newport defender has netted 17 times in 175 appearances for the Wanderers since his arrival in June 2021.
The Wales international has 16 caps and played the full 90 minutes in the nation's recent World Cup qualifier against North Macedonia. He praised the club, saying the stadium feels like home for him and his family.