The Hammers have made a brilliant start to the new campaign, but Terzic is not entirely satisfied by what he has witnessed so far.
The Croatian coach, who was brought in as part of Slaven Bilic's coaching staff, is a perfectionist, and he wants to see the team become much more solid in defence after the international break.
“We definitely want to do better, because you always want to do better," he said. "We have always had similar games – either we’ve been winning early in the games, like we did at Arsenal, Liverpool, Manchester City and home to Newcastle by scoring the first goal and producing a good performance, or we have been losing and two-down.
“Sometimes we have come back very well, and other times it has taken a bit longer to come back and we came back in the second half, but they were the similar style of games.
“We have to find a way in between to have a good game for the whole 90 minutes. Of course we would like to score the first goal in every game, so we need to defend better.”
West Ham have conceded 11 times over their first eight Premier League games this season, and Leicester City are the only team in the top-half of the table to have let in more goals.
Despite, the porous nature of their defence, the Hammers have still have had plenty to be encouraged by over the opening few weeks.
West Ham are unbeaten away from home in the league this season, and their attacking class has made them a threat to every side they have faced.
Bilic's side have netted a staggering 17 goals already this term, and if they can continue to find the net with such regularity they should remain in the upper echelons of the table for the rest of the campaign.