An acoustic treatment panel intended to be disposed on at least one wall of an aircraft propulsion unit in contact with a fluidic flow, the panel including a first, acoustically reflective skin, a second, acoustically porous skin intended to be in contact with the fluidic flow, and a honeycomb structure extending between the first skin and the second skin and having a plurality of cavities. The panel includes at least one acoustically transparent reinforcing wall passing through a plurality of cavities of the honeycomb structure and extending from the second skin to the first skin, forming a non-orthogonal angle with the first and second skins.