Fleetwood manager Graham Alexander said his side have to learn to shut up shop if they are to maintain their promotion push after a 2-0 defeat at Accrington.
The Cod Army are still in a good position, but have leaked six goals in the last two games.
Danny Webber scored a 75th-minute penalty before Kayode Odejayi put the game out of Fleetwood's reach eight minutes from time.
"We have not got to that steeliness at the moment and that is something we have got to address," said Alexander.
"We need to get an unbeaten run going as we keep winning a few and then losing.
"I'm disappointed against Accrington as, up to the penalty, I couldn't see us getting beaten.
"But mistakes are proving costly and we are conceding silly goals.
"We are the top scorers in the division and we are winning a lot of games, but we can't concede goals like we are.
"We have to look at this and put it right. The positives from this are we know the mistakes can be cut out and we can rectify this."
James Beattie's Accrington are now eight games unbeaten in the league and are five points off the bottom two after propping up the league last month.
"I'm proud of the lads and they are starting to believe in themselves and we can see it in the results," said the Stanley manager.
"Fleetwood started well but we handled it and we got through to half-time and there were a few words said in the dressing room.
"We have a great team spirit and the lads on the bench like Danny Webber and James Gray have shown a great attitude.
"I'm delighted for Danny as he has come on and had a positive impact and there was a lot more happiness in the dressing room after the game than at half-time."
Substitute Webber scored from the spot after 75 minutes after Charlie Taylor had fouled Peter Murphy in the area.
And Odejayi turned and slid home the second from close range after 82 minutes to make it five wins in the last six league games for Stanley.
But promotion-chasing Fleetwood could only blame themselves for not taking their chances after Saturday's hat-trick hero Antoni Sarcevic blasted a shot against the crossbar after 22 minutes.
On-loan Blackpool striker Nathan Tyson dragged an effort wide, while Sarcevic also had a goalbound header cleared off the line by Accrington on the stroke of half-time.
There were limited chances after the break before Webber and Odejayi pounced.