The fact that children are drawn to join the ranks of armed forces or non-state armed groups is a scourge that persists despite concerted efforts to eradicate the practice. No facet of this reality is perhaps more shocking than children’s direct participation in hostility, in that it raises the spectre of combatants directly targeting children. International humanitarian law has been largely silent on this specific aspect of child soldiering, leaving armed forces to improvise their stance when confronted with child soldiers on the battlefield. The Canadian Armed Forces in 2017 adopted what is said to be the first official military doctrine on child soldiers. This article analyzes this doctrine in light of the regulation of the use of force against child soldiers under international humanitarian law. It assesses whether children can ever be full-fledge combatants, when they can be considered civilians directly participating in hostilities, and, if children can be directly targeted, what limits humanitarian law imposes on the means and measures of war employed against them.