2018. Despite being transfer-listed, Pett remained at Stevenage for the start of the 2017–18 season, scoring the club's first goal of the new campaign when he capitalised on a defensive mistake to open the scoring in an eventual 3–3 draw with Newport County on 5 August 2017. Pett went on to score seven times in 34 appearances during the first half of the campaign, including his first brace for Stevenage in a 4–1 win against Cheltenham Town on 1 January 2018. During his three-and-a-half years with Stevenage, Pett made 159 appearances and scored 22 goals. Lincoln City In January 2018, Pett informed Stevenage that he was going to be leaving the club when his contract expired later in June that year, which would have meant he would have left on a free transfer upon the expiry of his contract. Stevenage received a "significant five-figure" offer for Pett from fellow League Two club Lincoln City towards the end of the month, which was accepted. Pett agreed personal terms and subsequently signed for Lincoln on a -year deal on 31 January 2018. He made his Lincoln debut as a 61st-minute substitute in a 2–2 draw with Swindon Town at Sincil Bank on 3 February 2018. Pett scored his first goal for Lincoln in the club's 1–1 home draw with Yeovil Town on the final day of the regular season. Pett's goal, a 20-yard equaliser late in the second half, helped Lincoln earn the point they needed to secure their place in the League Two play-offs. Lincoln would ultimately lose to Exeter City at the semi-final stage, with Pett coming on as a substitute in both matches. He made 11 appearances for Lincoln during the second half of the 2017–18 season, scoring once. Pett scored his first goal of the 2018–19 campaign in a 2–1 away victory at Macclesfield Town on 15 September 2018. He was named as the Professional Footballers' Association (PFA) Fans' Player of the Month for September. He made 51 appearances during his first full season at Lincoln, scoring four times as they finished the season as League Two champions. He suffered back problems ahead of the 2019–20 season and was then ruled out of action for up to six weeks with a knee injury, suffering a medial ligament tear. During this time he was studying mental health with Middlesex University, during which he was writing a dissertation. By the