A gas turbine engine includes an annular structure disposed around an engine central longitudinal axis of the gas turbine engine. The annular structure defines an annular channel and comprises a first density, according to various embodiments. The gas turbine engine may further include a weight-saving filler disposed within the annular channel. The weight-saving filler may have a second density that is less than the first density. The gas turbine engine may further include an annular retention strap disposed around the engine central longitudinal axis of the gas turbine engine. The annular retention strap is at least partially embedded in the weight-saving filler, according to various embodiments.