A binary Al-1.7Li alloy has been studied after ageing at 150 C and subsequently exposing for 1000h at 100degreesC. The exposure treatment caused embrittlement of the alloy, and attempts to alleviate this embrittlement by a full reversion heat treatment at 230degreesC has been investigated. Electrical resistivity measurements, mechanical property determination, and TEM have been used to monitor the processes taking place.