Reja offered his resignation on Monday after being jeered by some fans during the home defeat to Genoa on Sunday.
Lazio president Claudio Lotito rejected the offer and persuaded Reja to remain in charge at the Stadio Olimpico.
Reja has revealed the issue has been resolved and he is focused on getting back to winning ways.
"I had a meeting with the squad and the president. After some clarifications, we have decided to continue my adventure at Lazio," said Reja.
"The discomfort is not in working here. The picture is good in Rome, it is just the frame that is rotten.
"I must not only win, I must win big, and this can not be done."