The 22-year-old is confident he fixed the issue heading into 2019.
"That's not a concern. My concern is on winning," Jackson said, via the team's official website. "I got it fixed. Got to wait till the regular season to see what goes on."
Coach John Harbaugh wasn't as certain as Jackson but noted the QB's improved ball security.
"I think it's been way better. Just watching the practices, you probably saw it," Harbaugh said. "Lamar makes very few mistakes with ball handling right now. The snaps have been much more accurate than they have in the past, so that starts everything off on the right foot. You haven't seen a lot of the more complicated ball-handling plays, but the ones we have run have been well done."
When the Ravens bust out their more complicated plays for the regular season, Jackson's first goal will not be fumbling the ball away as much as he did as a rookie.