The R's have conceded 22 times in the Championship so far this season, the joint-highest amount of any side in the division, with their defence looking very shaky.
However, Luongo says that Chris Ramsey has been trying to make sure his side are tighter at the back, and these improvements were shown in QPR's latest 0-0 draw against Sheffield Wednesday.
"All week we’ve been addressing why we’re conceding such a lot of goals," the Australian international said. "We’ve made a few tweaks here and there and it paid off.
“The boys at the back were really good, they didn’t switch off once in the game. When there was an error, they were sharp to fix it and deal with it."
Even though the R's were able to claim a much needed clean sheet against Wednesday, their supporters were still not entirely satisfied with their performance.
Boos could be heard at Loftus Road, with Ramsey continuing to fall under mounting pressure as a result of his side's poor start.
QPR have won just once in their last seven matches, and they are currently sat in 10th place in the Championship table.
With the pressure on the London club to get promoted this season, there is a realisation that their form will need to improve considerably in the near future, with the R's next match coming against Milton Keynes Dons at the weekend.