The Germans top Group C from Austria, but they conceded three goals in the recent friendly against Paraguay, which Low has used as a warning for his players.
"It's pretty clear that our defence is an issue," Bundesliga.de quotes Low as saying. "We weren't tight enough against Paraguay. Whenever that has happened, we've played badly.
"When we've been compact, we've played well and won. These are the basics we've talked about and tried to get right in training.
"We have to avoid the simple, individual errors we made against Paraguay. I'm sure it will go better for us on Friday. The team have taken the advice on board."
Germany are undefeated in the group, with five wins and a draw so far.