This paper presents how autonomy adaptation can be useful to enhance the fault tolerance of autonomous mobile robots. For that, we proposed a global and structured methodology which allows integrating specific fault tolerant mechanisms into an adaptive control architecture. When a problem is detected, the autonomous behavior of the robot is automatically adapted to overcome it. The human operator can punctually or definitively be inserted in the control loop to replace the damaged functionalities and to ensure the success of the mission. Experimental results on a mobile robot are proposed to illustrate the autonomy adaptation.