In this technical note, cone-copositive piecewise quadratic Lyapunov functions (PWQ-LFs) for the stability analysis of conewise linear systems are proposed. The existence of a PWQ-LF is formulated as the feasibility of a cone-copositive programming problem which is represented in terms of linear matrix inequalities. A constructive procedure for its solution is provided. Examples show the effectiveness of the approach, also in the case of uncertain conewise linear systems.