Chris Cohen had given the visitors the lead before Jamie Ward responded but at the end of a turbulent week in which the chief executive and chief scout left the club, McLeish was pleased to end a run of three defeats.
Forest sit five points outside the play-off zone in 10th place and the Scot said new recruits were needed to mount a serious promotion challenge.
"I am going to try and be as busy as I can," McLeish said. "I spoke to the owners today after the game and they are very keen for us to add players to the squad.
"I think these guys have got a good chance of climbing further up the table but I would like to have an even better chance by adding new players.
"If we are going to be in amongst the challengers for the big prize, we need to score more goals.
"It was a great show of character from the players today, the commitment they showed right to the final whistle was terrific. Hopefully they are starting to believe in themselves a bit more."