diff --git a/db/migrate/20160220174730_create_accounts.rb b/db/migrate/20160220174730_create_accounts.rb
index 65c15f3e8a90a82b6b55499c083cad03fe361128..daf7c655262dd2ccc3dae966f2d8e88503bb2afc 100644
--- a/db/migrate/20160220174730_create_accounts.rb
+++ b/db/migrate/20160220174730_create_accounts.rb
@@ -1,4 +1,4 @@
-class CreateAccounts < ActiveRecord::Migration
+class CreateAccounts < ActiveRecord::Migration[4.2]
   def change
     create_table :accounts do |t|
       t.string :username, null: false, default: ''
diff --git a/db/migrate/20160220211917_create_statuses.rb b/db/migrate/20160220211917_create_statuses.rb
index 5e62e95be1230af3e57671a8372af876642cd94d..b1746856873286b0f4dc42e7c78a834471755410 100644
--- a/db/migrate/20160220211917_create_statuses.rb
+++ b/db/migrate/20160220211917_create_statuses.rb
@@ -1,4 +1,4 @@
-class CreateStatuses < ActiveRecord::Migration
+class CreateStatuses < ActiveRecord::Migration[4.2]
   def change
     create_table :statuses do |t|
       t.string :uri, null: false, default: ''
diff --git a/db/migrate/20160221003140_create_users.rb b/db/migrate/20160221003140_create_users.rb
index c9750c6238bf1f716ebb8f3843f2d0206d4ea92f..267466a9491efb1ccfcc9ae5abb71603dc811486 100644
--- a/db/migrate/20160221003140_create_users.rb
+++ b/db/migrate/20160221003140_create_users.rb
@@ -1,4 +1,4 @@
-class CreateUsers < ActiveRecord::Migration
+class CreateUsers < ActiveRecord::Migration[4.2]
   def change
     create_table :users do |t|
       t.string :email, null: false, default: ''
diff --git a/db/migrate/20160221003621_create_follows.rb b/db/migrate/20160221003621_create_follows.rb
index afec3dee031843c2893de9086c0754fabf590b42..17287d09bc368f47049fdbff9a0b52745ea21d5e 100644
--- a/db/migrate/20160221003621_create_follows.rb
+++ b/db/migrate/20160221003621_create_follows.rb
@@ -1,4 +1,4 @@
-class CreateFollows < ActiveRecord::Migration
+class CreateFollows < ActiveRecord::Migration[4.2]
   def change
     create_table :follows do |t|
       t.integer :account_id, null: false
diff --git a/db/migrate/20160222122600_create_stream_entries.rb b/db/migrate/20160222122600_create_stream_entries.rb
index 10a6862d9f64c3b50a288c69def1201ae595f9b1..00782abc33fa333f4646c811567ae694bc9a5f4b 100644
--- a/db/migrate/20160222122600_create_stream_entries.rb
+++ b/db/migrate/20160222122600_create_stream_entries.rb
@@ -1,4 +1,4 @@
-class CreateStreamEntries < ActiveRecord::Migration
+class CreateStreamEntries < ActiveRecord::Migration[4.2]
   def change
     create_table :stream_entries do |t|
       t.integer :account_id
diff --git a/db/migrate/20160222143943_add_profile_fields_to_accounts.rb b/db/migrate/20160222143943_add_profile_fields_to_accounts.rb
index 221142bdd4b79735ce609f7d8f8b49cd9ddc9e18..cf279a535da928330a7c83bb6f517b6eeb855fe3 100644
--- a/db/migrate/20160222143943_add_profile_fields_to_accounts.rb
+++ b/db/migrate/20160222143943_add_profile_fields_to_accounts.rb
@@ -1,4 +1,4 @@
-class AddProfileFieldsToAccounts < ActiveRecord::Migration
+class AddProfileFieldsToAccounts < ActiveRecord::Migration[4.2]
   def change
     add_column :accounts, :note, :text, null: false, default: ''
     add_column :accounts, :display_name, :string, null: false, default: ''
diff --git a/db/migrate/20160223162837_add_metadata_to_statuses.rb b/db/migrate/20160223162837_add_metadata_to_statuses.rb
index 7120e582a49a52284fae41c6a1350fd5bda00be8..d11d5f5cdf9ea21c7c24475d97c3c21466dc873a 100644
--- a/db/migrate/20160223162837_add_metadata_to_statuses.rb
+++ b/db/migrate/20160223162837_add_metadata_to_statuses.rb
@@ -1,4 +1,4 @@
-class AddMetadataToStatuses < ActiveRecord::Migration
+class AddMetadataToStatuses < ActiveRecord::Migration[4.2]
   def change
     add_column :statuses, :in_reply_to_id, :integer, null: true
     add_column :statuses, :reblog_of_id, :integer, null: true
diff --git a/db/migrate/20160223164502_make_uris_nullable_in_statuses.rb b/db/migrate/20160223164502_make_uris_nullable_in_statuses.rb
index 0fc1c39c3f0430a61b11a08b2ce117cb2dcfb516..24b9b6e190ad089d7300965c2448682df6281ebf 100644
--- a/db/migrate/20160223164502_make_uris_nullable_in_statuses.rb
+++ b/db/migrate/20160223164502_make_uris_nullable_in_statuses.rb
@@ -1,4 +1,4 @@
-class MakeUrisNullableInStatuses < ActiveRecord::Migration
+class MakeUrisNullableInStatuses < ActiveRecord::Migration[4.2]
   def change
     change_column :statuses, :uri, :string, null: true, default: nil
   end
diff --git a/db/migrate/20160223165723_add_url_to_statuses.rb b/db/migrate/20160223165723_add_url_to_statuses.rb
index a5aa1613a9298948004866b0abc2f122a98c3862..80f4b3289e5bb51d3dd2b4b11383927bfc543bfe 100644
--- a/db/migrate/20160223165723_add_url_to_statuses.rb
+++ b/db/migrate/20160223165723_add_url_to_statuses.rb
@@ -1,4 +1,4 @@
-class AddUrlToStatuses < ActiveRecord::Migration
+class AddUrlToStatuses < ActiveRecord::Migration[4.2]
   def change
     add_column :statuses, :url, :string, null: true, default: nil
   end
diff --git a/db/migrate/20160223165855_add_url_to_accounts.rb b/db/migrate/20160223165855_add_url_to_accounts.rb
index 59dd2b97b9b4d9ab775d2ba56e4a63c42b4f824c..c81b1c64fc7034f5c51348b894cb0d87127bbb82 100644
--- a/db/migrate/20160223165855_add_url_to_accounts.rb
+++ b/db/migrate/20160223165855_add_url_to_accounts.rb
@@ -1,4 +1,4 @@
-class AddUrlToAccounts < ActiveRecord::Migration
+class AddUrlToAccounts < ActiveRecord::Migration[4.2]
   def change
     add_column :accounts, :url, :string, null: true, default: nil
   end
diff --git a/db/migrate/20160223171800_create_favourites.rb b/db/migrate/20160223171800_create_favourites.rb
index bb35f491fe57d6a453815e56e9d11e9ab79d5c4a..64f5cf11970957c3470318293f59e2d31cdbb4db 100644
--- a/db/migrate/20160223171800_create_favourites.rb
+++ b/db/migrate/20160223171800_create_favourites.rb
@@ -1,4 +1,4 @@
-class CreateFavourites < ActiveRecord::Migration
+class CreateFavourites < ActiveRecord::Migration[4.2]
   def change
     create_table :favourites do |t|
       t.integer :account_id, null: false
diff --git a/db/migrate/20160224223247_create_mentions.rb b/db/migrate/20160224223247_create_mentions.rb
index 095f6b7d269c8d0d7bd6a9a4935787005053afda..6dd742d3b1b1593a8968d54d9f25ab51107d0a89 100644
--- a/db/migrate/20160224223247_create_mentions.rb
+++ b/db/migrate/20160224223247_create_mentions.rb
@@ -1,4 +1,4 @@
-class CreateMentions < ActiveRecord::Migration
+class CreateMentions < ActiveRecord::Migration[4.2]
   def change
     create_table :mentions do |t|
       t.integer :account_id
diff --git a/db/migrate/20160227230233_add_attachment_avatar_to_accounts.rb b/db/migrate/20160227230233_add_attachment_avatar_to_accounts.rb
index 99d88e5ecf26c53e04df792284f7062f6e5c0883..c107c4c7fa77eb78c223a488972a91ea2eeb54f2 100644
--- a/db/migrate/20160227230233_add_attachment_avatar_to_accounts.rb
+++ b/db/migrate/20160227230233_add_attachment_avatar_to_accounts.rb
@@ -1,4 +1,4 @@
-class AddAttachmentAvatarToAccounts < ActiveRecord::Migration
+class AddAttachmentAvatarToAccounts < ActiveRecord::Migration[4.2]
   def self.up
     change_table :accounts do |t|
       t.attachment :avatar
diff --git a/db/migrate/20160305115639_add_devise_to_users.rb b/db/migrate/20160305115639_add_devise_to_users.rb
index 236a4b27c3240c9f0d7e5521a5b2003495609da3..0e12e60536cfe3e0b05bb23bbedaae0a6af0ac99 100644
--- a/db/migrate/20160305115639_add_devise_to_users.rb
+++ b/db/migrate/20160305115639_add_devise_to_users.rb
@@ -1,4 +1,4 @@
-class AddDeviseToUsers < ActiveRecord::Migration
+class AddDeviseToUsers < ActiveRecord::Migration[4.2]
   def self.up
     change_table(:users) do |t|
       ## Database authenticatable
diff --git a/db/migrate/20160306172223_create_doorkeeper_tables.rb b/db/migrate/20160306172223_create_doorkeeper_tables.rb
index d89b005c3c1e3bdbc89902a98c3af5d3e00932f9..9e173a43f32ea53675cc6711caa58d1259c5d17c 100644
--- a/db/migrate/20160306172223_create_doorkeeper_tables.rb
+++ b/db/migrate/20160306172223_create_doorkeeper_tables.rb
@@ -1,4 +1,4 @@
-class CreateDoorkeeperTables < ActiveRecord::Migration
+class CreateDoorkeeperTables < ActiveRecord::Migration[4.2]
   def change
     create_table :oauth_applications do |t|
       t.string  :name,         null: false
diff --git a/db/migrate/20160312193225_add_attachment_header_to_accounts.rb b/db/migrate/20160312193225_add_attachment_header_to_accounts.rb
index bdd09c3672cdf9f595448d06b09c530f29da2e96..ac9562cbbee7bd04c1d62c44335d1a147e2cce54 100644
--- a/db/migrate/20160312193225_add_attachment_header_to_accounts.rb
+++ b/db/migrate/20160312193225_add_attachment_header_to_accounts.rb
@@ -1,4 +1,4 @@
-class AddAttachmentHeaderToAccounts < ActiveRecord::Migration
+class AddAttachmentHeaderToAccounts < ActiveRecord::Migration[4.2]
   def self.up
     change_table :accounts do |t|
       t.attachment :header
diff --git a/db/migrate/20160314164231_add_owner_to_application.rb b/db/migrate/20160314164231_add_owner_to_application.rb
index 7d5e6d07d0f21ae50a08ceb958b2f9ddbb1dc8c5..1919f09a170d9364fab77dbda30b37fe0399cab3 100644
--- a/db/migrate/20160314164231_add_owner_to_application.rb
+++ b/db/migrate/20160314164231_add_owner_to_application.rb
@@ -1,4 +1,4 @@
-class AddOwnerToApplication < ActiveRecord::Migration
+class AddOwnerToApplication < ActiveRecord::Migration[4.2]
   def change
     add_column :oauth_applications, :owner_id, :integer, null: true
     add_column :oauth_applications, :owner_type, :string, null: true
diff --git a/db/migrate/20160316103650_add_missing_indices.rb b/db/migrate/20160316103650_add_missing_indices.rb
index 1902418335728e1b239289040198a7839ac7c089..8b6bc5771b5ffda1eab0ed0892d205fbe692fcdd 100644
--- a/db/migrate/20160316103650_add_missing_indices.rb
+++ b/db/migrate/20160316103650_add_missing_indices.rb
@@ -1,4 +1,4 @@
-class AddMissingIndices < ActiveRecord::Migration
+class AddMissingIndices < ActiveRecord::Migration[4.2]
   def change
     add_index :users, :account_id
     add_index :statuses, :account_id
diff --git a/db/migrate/20160322193748_add_avatar_remote_url_to_accounts.rb b/db/migrate/20160322193748_add_avatar_remote_url_to_accounts.rb
index 9dc4b027f0226c5ccbf447f12891fe7695dd5ec6..f9c213d9b47e6ffabe78879377d46b24690d6712 100644
--- a/db/migrate/20160322193748_add_avatar_remote_url_to_accounts.rb
+++ b/db/migrate/20160322193748_add_avatar_remote_url_to_accounts.rb
@@ -1,4 +1,4 @@
-class AddAvatarRemoteUrlToAccounts < ActiveRecord::Migration
+class AddAvatarRemoteUrlToAccounts < ActiveRecord::Migration[4.2]
   def change
     add_column :accounts, :avatar_remote_url, :string, null: true, default: nil
   end
diff --git a/db/migrate/20160325130944_add_admin_to_users.rb b/db/migrate/20160325130944_add_admin_to_users.rb
index e386d33dda74a009fa4b9d985e54911b154a3e38..b0cd35e0082bba134a7cbefccd086f2d9fd2f38d 100644
--- a/db/migrate/20160325130944_add_admin_to_users.rb
+++ b/db/migrate/20160325130944_add_admin_to_users.rb
@@ -1,4 +1,4 @@
-class AddAdminToUsers < ActiveRecord::Migration
+class AddAdminToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :admin, :boolean, default: false
   end
diff --git a/db/migrate/20161006213403_rails_settings_migration.rb b/db/migrate/20161006213403_rails_settings_migration.rb
index 3bfd8af8ecb53a3adb4acebe1f8ec5a25a0bba85..3b2e637fc7c3b6d7d8f996cf18c527266f6abe80 100644
--- a/db/migrate/20161006213403_rails_settings_migration.rb
+++ b/db/migrate/20161006213403_rails_settings_migration.rb
@@ -1,7 +1,7 @@
 MIGRATION_BASE_CLASS = if ActiveRecord::VERSION::MAJOR >= 5
   ActiveRecord::Migration[5.0]
 else
-  ActiveRecord::Migration
+  ActiveRecord::Migration[4.2]
 end
 
 class RailsSettingsMigration < MIGRATION_BASE_CLASS
diff --git a/db/migrate/20170112154826_migrate_settings.rb b/db/migrate/20170112154826_migrate_settings.rb
index f6f6ed5315e1c75163e4c35e87a36b93bb47ac1c..0f5afe1d39b480a12d3da10bca0b351c9327cb5a 100644
--- a/db/migrate/20170112154826_migrate_settings.rb
+++ b/db/migrate/20170112154826_migrate_settings.rb
@@ -1,4 +1,4 @@
-class MigrateSettings < ActiveRecord::Migration
+class MigrateSettings < ActiveRecord::Migration[4.2]
   def up
     remove_index :settings, [:target_type, :target_id, :var]
     rename_column :settings, :target_id, :thing_id
diff --git a/db/migrate/20170330164118_add_attachment_data_to_imports.rb b/db/migrate/20170330164118_add_attachment_data_to_imports.rb
index 4850b0663d0c189bf526db7f12e073fd7c966c7c..2deda18861227661e190d8a6b10c980920555515 100644
--- a/db/migrate/20170330164118_add_attachment_data_to_imports.rb
+++ b/db/migrate/20170330164118_add_attachment_data_to_imports.rb
@@ -1,4 +1,4 @@
-class AddAttachmentDataToImports < ActiveRecord::Migration
+class AddAttachmentDataToImports < ActiveRecord::Migration[4.2]
   def self.up
     change_table :imports do |t|
       t.attachment :data