diff --git a/lib/tasks/standalone_migrations.rb b/lib/tasks/standalone_migrations.rb
index 2c6461c..c3758b8 100644
--- a/lib/tasks/standalone_migrations.rb
+++ b/lib/tasks/standalone_migrations.rb
@@ -14,7 +14,7 @@ def standalone_configurator
 
 module Rails
   def self.env
-    s = (ENV['RAILS_ENV'] || ENV['DB'] || 'development').dup # env is frozen -> dup
+    s = (ENV['RAILS_ENV'] || ENV['RACK_ENV'] || ENV['DB'] || 'development').dup # env is frozen -> dup
     def s.development?; self == 'development';end
     s
   end