Although his side secured a 48-15 win over the Sharks in Dunedin on Friday, Highlanders boss Jamie feels there is still room for improvement.
The Highlanders delivered a superb display of counter-attacking rugby and scored seven tries against the struggling visitors.
The home side's effort was a fine response after they suffered a 31-18 defeat to the Brumbies last weekend but Joseph isn't entirely happy.
"Really, both teams were under a bit of pressure and we didn't get the result we were after last week and they've had a couple of losses as well," he told Fairfax Media.
"I'm really proud of our forward pack. If we didn't give silly penalties away it would have been a perfect performance for me."
Fly-half Lima Sopoaga, who kicked 13 points in the victory, said the win came at the right time ahead of their tour to South Africa where they will face the Lions and Cheetahs.
"It's a bit of relief to get the win and prepare to go on the road," he said.
"We did everything the coaches asked, we lifted when we had to. When opportunities came we struck.
"We know they are big up front and with any African side, you have to move them around.
"I thought we did that really nicely and when we executed nicely we put them away."