Preheat oven to 350 F. Roll pie crust into a round 9-inch pie plate. In a medium bowl, combine blueberries, sugar, cornstarch, and lemon juice.
Pour blueberry mixture into the pie crust. In a small bowl, combine flour, brown sugar, cinnamon, and melted butter until crumbly.
Sprinkle crumble over pie. Bake for 50-55 minutes.