The Foxes were leading 1-0 at Brighton last weekend courtesy of James' goal until an 88th-minute equaliser from Kazenga LuaLua denied them all three points.
It was the fifth time in the last 12 league matches that Leicester had conceded in the final five minutes, potentially costing them seven points at what is a crucial stage of the season.
"We have to take positives from the Brighton game because we played really well and deserved three points," James, 21, told reporters ahead of the visit of Birmingham on Friday night.
"But we conceded very late again. We have to cut out these last-minute goals.
"We were in control of the game and it is that one little lapse which has cost us the three points. We have to go to places like Brighton and take 1-0 wins."