Queen of the South say they held off competition from clubs in England and Scotland to sign Dumbarton goalkeeper Alan Martin.
Nicky Clark's injury-time winner sees Dunfermline beat Queen of the South to confirm fifth place in the Championship.
Dunfermline end their home campaign on a high with a 3-1 win over play-off bound Morton.
Falkirk forward Myles Hippolyte will miss the final two Championship games of the season after accepting a two-game ban for diving.
Two second-half goals help Falkirk to keep their grip on second place in the Championship as they win away to Dunfermline.
Dumbarton slip into the Scottish Championship relegation play-off berth with a home defeat by Dunfermline Athletic.