In the previous work we presented a new gait for humanoid robots, such as the Nao developed by Aldebaran. This new gait implemented on a Nao, reduces the energy consumption by 41 %. Then main feature of the new gait is the absence of an area of support. The foot can rotate freely around the ankle joint. This feature makes the gait suited for uneven terrains.Stability is an important aspect of walking on uneven terrains, especially the lateral stability. During the single support phase of a step the robot balances above the stance leg. If the robot steps on a bump or in a hole, the lateral stability may be disrupted. This paper presents a controller that guarantees the lateral stability in the present of such disruptions.