The stretch of the TT course between Bishopscourt and Rhencullen will be shut on Wednesday morning while a tree is removed from the area.
The emergency road closure will be in place between 9.30am and 1pm.
A Department of Infrastructure spokesperson said: ‘A road closure will be in force to facilitate the removal of the tree, which poses a danger of falling onto the highway.
‘The Orrisdale Loop Road will be accessible, but please be aware that this road is not suitable for HGVs or large vehicles.
‘The map below shows the area in RED that will be closed between each of the junctions of the Orrisdale Loop Road.’