--- a/src/CompositeTest.hs
+++ b/src/CompositeTest.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-} -- FIXME
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
 module CompositeTest where
 
--- a/src/CustomPersistFieldTest.hs
+++ b/src/CustomPersistFieldTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module CustomPersistFieldTest (specsWith, customFieldMigrate) where
 
--- a/src/CustomPrimaryKeyReferenceTest.hs
+++ b/src/CustomPrimaryKeyReferenceTest.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
 -- This test is based on this issue: https://github.com/yesodweb/persistent/issues/421
 -- The primary thing this is testing is the migration, thus the test code itself being mostly negligible.
--- a/src/DataTypeTest.hs
+++ b/src/DataTypeTest.hs
@@ -1,5 +1,8 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module DataTypeTest
     ( specsWith
--- a/src/EmbedOrderTest.hs
+++ b/src/EmbedOrderTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module EmbedOrderTest (specsWith, embedOrderMigrate, cleanDB) where
 
--- a/src/EmbedTest.hs
+++ b/src/EmbedTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-orphans -O0 #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module EmbedTest (specsWith, cleanDB, embedMigrate) where
--- a/src/EmptyEntityTest.hs
+++ b/src/EmptyEntityTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module EmptyEntityTest (specsWith, migration, cleanDB) where
 
--- a/src/EntityEmbedTest.hs
+++ b/src/EntityEmbedTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module EntityEmbedTest where
 
 -- because we are using a type alias we need to declare in a separate module
--- a/src/EquivalentTypeTest.hs
+++ b/src/EquivalentTypeTest.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 
--- a/src/HtmlTest.hs
+++ b/src/HtmlTest.hs
@@ -1,4 +1,8 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
+
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module HtmlTest (specsWith, cleanDB, htmlMigrate) where
 
--- a/src/LargeNumberTest.hs
+++ b/src/LargeNumberTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module LargeNumberTest where
 
 import Data.Word
--- a/src/MaxLenTest.hs
+++ b/src/MaxLenTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 
 module MaxLenTest (specsWith, maxlenMigrate) where
--- a/src/MigrationColumnLengthTest.hs
+++ b/src/MigrationColumnLengthTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module MigrationColumnLengthTest where
 
 import qualified Data.Text as T
--- a/src/MigrationIdempotencyTest.hs
+++ b/src/MigrationIdempotencyTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module MigrationIdempotencyTest where
 
 import qualified Data.Text as T
--- a/src/MigrationOnlyTest.hs
+++ b/src/MigrationOnlyTest.hs
@@ -1,5 +1,8 @@
 {-# LANGUAGE UndecidableInstances #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module MigrationOnlyTest (specsWith, migrateAll1, migrateAll2) where
 
 import qualified Data.Text as T
--- a/src/MigrationTest.hs
+++ b/src/MigrationTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module MigrationTest where
 
 import Database.Persist.TH
--- a/src/PersistUniqueTest.hs
+++ b/src/PersistUniqueTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module PersistUniqueTest where
 
 import Init
--- a/src/PersistentTestModels.hs
+++ b/src/PersistentTestModels.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE UndecidableInstances #-} -- FIXME
+{-# LANGUAGE DerivingStrategies #-}
 module PersistentTestModels where
 
 import Data.Aeson
--- a/src/PrimaryTest.hs
+++ b/src/PrimaryTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module PrimaryTest where
 
 import Init
--- a/src/Recursive.hs
+++ b/src/Recursive.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module Recursive (specsWith, recursiveMigrate, cleanup) where
 
--- a/src/RenameTest.hs
+++ b/src/RenameTest.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module RenameTest where
 
 import qualified Data.Map as Map
--- a/src/SumTypeTest.hs
+++ b/src/SumTypeTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 module SumTypeTest (specsWith, sumTypeMigrate) where
 
--- a/src/TransactionLevelTest.hs
+++ b/src/TransactionLevelTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 
 module TransactionLevelTest where
 
--- a/src/TreeTest.hs
+++ b/src/TreeTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-} -- FIXME
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module TreeTest where
 
 import Database.Persist.TH (mkDeleteCascade)
--- a/src/UniqueTest.hs
+++ b/src/UniqueTest.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module UniqueTest where
 
 import Init