For the second match in a row, the Gunners came from a goal behind to gain a positive result, with Tuesday night's comeback taking place in the Champions League against PSG.
Alexis Sanchez's 78th-minute strike gave Arsene Wenger's side a handy point on the road but stand-in skipper Koscielny says these sorts of efforts can be avoided if everybody is switched on from the beginning.
"It's like against Southampton we slept and we need to change this in the future," he told BT Sport.
"If you start 1-0 down it's difficult to win. We need be strong from the first minute until the end.
"I think during the game we played well, but it was a difficult start."