diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index 10073e2b371b2..8dade3b576285 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -546,14 +546,14 @@ class << self
 
       def migrate(migrations_paths, target_version = nil, &block)
         case
-          when target_version.nil?
-            up(migrations_paths, target_version, &block)
-          when current_version == 0 && target_version == 0
-            []
-          when current_version > target_version
-            down(migrations_paths, target_version, &block)
-          else
-            up(migrations_paths, target_version, &block)
+        when target_version.nil?
+          up(migrations_paths, target_version, &block)
+        when current_version == 0 && target_version == 0
+          []
+        when current_version > target_version
+          down(migrations_paths, target_version, &block)
+        else
+          up(migrations_paths, target_version, &block)
         end
       end
 
@@ -566,15 +566,19 @@ def forward(migrations_paths, steps=1)
       end
 
       def up(migrations_paths, target_version = nil, &block)
-        self.new(:up, migrations_paths, target_version).migrate(&block)
+        self.new(:up, migrations(migrations_paths), target_version).migrate(&block)
       end
 
       def down(migrations_paths, target_version = nil, &block)
-        self.new(:down, migrations_paths, target_version).migrate(&block)
+        self.new(:down, migrations(migrations_paths), target_version).migrate(&block)
       end
 
       def run(direction, migrations_paths, target_version)
-        self.new(direction, migrations_paths, target_version).run
+        self.new(direction, migrations(migrations_paths), target_version).run
+      end
+
+      def open(migrations_paths)
+        self.new(:up, migrations(migrations_paths), nil)
       end
 
       def schema_migrations_table_name
@@ -638,7 +642,7 @@ def migrations(paths)
       private
 
       def move(direction, migrations_paths, steps)
-        migrator = self.new(direction, migrations_paths)
+        migrator = self.new(direction, migrations(migrations_paths))
         start_index = migrator.migrations.index(migrator.current_migration)
 
         if start_index
@@ -649,10 +653,20 @@ def move(direction, migrations_paths, steps)
       end
     end
 
-    def initialize(direction, migrations_paths, target_version = nil)
+    def initialize(direction, migrations, target_version = nil)
       raise StandardError.new("This database does not yet support migrations") unless Base.connection.supports_migrations?
       Base.connection.initialize_schema_migrations_table
-      @direction, @migrations_paths, @target_version = direction, migrations_paths, target_version
+
+      @direction        = direction
+
+      if Array(migrations).grep(String).empty?
+        @migrations = migrations
+      else
+        ActiveSupport::Deprecation.warn "instantiate this class with a list of migrations"
+        @migrations = self.class.migrations(migrations)
+      end
+
+      @target_version   = target_version
     end
 
     def current_version
@@ -721,10 +735,7 @@ def migrate(&block)
     end
 
     def migrations
-      @migrations ||= begin
-        migrations = self.class.migrations(@migrations_paths)
-        down? ? migrations.reverse : migrations
-      end
+      down? ? @migrations.reverse : @migrations
     end
 
     def pending_migrations
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 41a060b706993..9038ebd32084c 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -890,7 +890,8 @@ def test_migrator_one_up_with_exception_and_rollback
   end
 
   def test_finds_migrations
-    migrations = ActiveRecord::Migrator.new(:up, MIGRATIONS_ROOT + "/valid").migrations
+    list = ActiveRecord::Migrator.migrations(MIGRATIONS_ROOT + "/valid")
+    migrations = ActiveRecord::Migrator.new(:up, list).migrations
 
     [[1, 'ValidPeopleHaveLastNames'], [2, 'WeNeedReminders'], [3, 'InnocentJointable']].each_with_index do |pair, i|
       assert_equal migrations[i].version, pair.first
@@ -899,7 +900,8 @@ def test_finds_migrations
   end
 
   def test_finds_migrations_in_subdirectories
-    migrations = ActiveRecord::Migrator.new(:up, MIGRATIONS_ROOT + "/valid_with_subdirectories").migrations
+    list = ActiveRecord::Migrator.migrations(MIGRATIONS_ROOT + "/valid_with_subdirectories")
+    migrations = ActiveRecord::Migrator.new(:up, list).migrations
 
     [[1, 'ValidPeopleHaveLastNames'], [2, 'WeNeedReminders'], [3, 'InnocentJointable']].each_with_index do |pair, i|
       assert_equal migrations[i].version, pair.first
@@ -909,7 +911,8 @@ def test_finds_migrations_in_subdirectories
 
   def test_finds_migrations_from_two_directories
     directories = [MIGRATIONS_ROOT + '/valid_with_timestamps', MIGRATIONS_ROOT + '/to_copy_with_timestamps']
-    migrations = ActiveRecord::Migrator.new(:up, directories).migrations
+    list = ActiveRecord::Migrator.migrations directories
+    migrations = ActiveRecord::Migrator.new(:up, list).migrations
 
     [[20090101010101, "PeopleHaveHobbies"],
      [20090101010202, "PeopleHaveDescriptions"],
@@ -932,13 +935,20 @@ def test_dump_schema_information_outputs_lexically_ordered_versions
 
   def test_finds_pending_migrations
     ActiveRecord::Migrator.up(MIGRATIONS_ROOT + "/interleaved/pass_2", 1)
-    migrations = ActiveRecord::Migrator.new(:up, MIGRATIONS_ROOT + "/interleaved/pass_2").pending_migrations
+    migration_list = ActiveRecord::Migrator.migrations(MIGRATIONS_ROOT + "/interleaved/pass_2")
+    migrations = ActiveRecord::Migrator.new(:up, migration_list).pending_migrations
 
     assert_equal 1, migrations.size
     assert_equal migrations[0].version, 3
     assert_equal migrations[0].name, 'InterleavedInnocentJointable'
   end
 
+  def test_deprecated_constructor
+    assert_deprecated do
+      ActiveRecord::Migrator.new(:up, MIGRATIONS_ROOT + "/interleaved/pass_2")
+    end
+  end
+
   def test_relative_migrations
     list = Dir.chdir(MIGRATIONS_ROOT) do
       ActiveRecord::Migrator.up("valid/", 1)