Annealing-induced　embrittlement　in　metallic　glasses　(MGs)　due　to　the　running　off　of　free　volume　(FV)　is　detrimental　to　their　practical　applications.　By　adding　crystalline　W　coatings,　we　demonstrated　that　the　majority　of　free　volume(FV)　could　be　preserved　and　redistributed　in　a　Zr50.7Cu28Ni9Al12.3　bulk　metallic　glass　(BMG)　upon　annealing　as,　thermodynamically,　itwas　unfavorable　for　the　FV　to　migrate　from　BMG　into　crystalline　W.　Correspondingly,　the　strength　and　ductility　of　the　BMG　were　both　enhanced　relative　to　as-cast　ones,　due　likely　to　decomposition　processes　such　as　the　formation　of　Zr-　and　Cu-rich　clusters　in　the　BMG.　The　results　of　this　study　may　be　applied　to　avoid　annealing-induced　embrittlement　in　BMGs　and　construct　a　simple　yet　effective　method　to　elevate　both　the　strength　and　ductility　of　BMGs.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.