During the British invasions of the Río de la Plata, Canaveris returned to work as a portero under the orders of Martín de Alzaga. His sons, José, Manuel, and Joaquín also participated in the defense of Buenos Aires in the regiments—Quinteros and Labradores, Húsares of Pueyrredón, and Cántabros Montañeses. The monk Martin Esparza, a relative of Canaveris's wife, was killed by British troops during the second invasion in the interior Convent of Santo Domingo.