diff --git a/.hlint.yaml b/.hlint.yaml
index 026b949..0b284f5 100644
--- a/.hlint.yaml
+++ b/.hlint.yaml
@@ -1,6 +1,7 @@
 # Help Hlint parse our code
 - arguments:
     - -XTypeApplications
+    - -XQuasiQuotes
 
 # Force qualified imports to be imported consistently.
 - modules:
diff --git a/back/package.yaml b/back/package.yaml
index 928f337..019f593 100644
--- a/back/package.yaml
+++ b/back/package.yaml
@@ -36,8 +36,24 @@ default-extensions:
 - ConstraintKinds
 - InstanceSigs
 - DerivingStrategies
-- TemplateHaskellQuotes
 - ScopedTypeVariables
+- OverloadedStrings
+- TypeOperators
+- KindSignatures
+- DataKinds
+- StandaloneDeriving
+- TypeFamilies
+- GADTs
+- DefaultSignatures
+- RoleAnnotations
+- QuasiQuotes
+- DeriveLift
+- PackageImports
+- OverloadedLabels
+- DeriveDataTypeable
+- PatternSynonyms
+- NamedFieldPuns
+- TemplateHaskell
 
 library:
   source-dirs: src
diff --git a/back/src/Guide/Api/Docs.hs b/back/src/Guide/Api/Docs.hs
index 76f7277..48401a7 100644
--- a/back/src/Guide/Api/Docs.hs
+++ b/back/src/Guide/Api/Docs.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-
 -- | Rendered documentation for the API.
 module Guide.Api.Docs
 (
diff --git a/back/src/Guide/Api/Error.hs b/back/src/Guide/Api/Error.hs
index dce8c8a..338e233 100644
--- a/back/src/Guide/Api/Error.hs
+++ b/back/src/Guide/Api/Error.hs
@@ -1,8 +1,4 @@
-{-# LANGUAGE DataKinds           #-}
 {-# LANGUAGE FlexibleInstances   #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilies        #-}
-{-# LANGUAGE TypeOperators       #-}
 
 
 module Guide.Api.Error
diff --git a/back/src/Guide/Api/Guider.hs b/back/src/Guide/Api/Guider.hs
index 7f8b426..f19ee96 100644
--- a/back/src/Guide/Api/Guider.hs
+++ b/back/src/Guide/Api/Guider.hs
@@ -1,6 +1,4 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE ScopedTypeVariables        #-}
 
 -- | 'Guider' monad with 'Config' to replace servant's 'Handler'.
 module Guide.Api.Guider
diff --git a/back/src/Guide/Api/Methods.hs b/back/src/Guide/Api/Methods.hs
index b5611ef..6b05b56 100644
--- a/back/src/Guide/Api/Methods.hs
+++ b/back/src/Guide/Api/Methods.hs
@@ -1,9 +1,4 @@
 {-# LANGUAGE AllowAmbiguousTypes #-}
-{-# LANGUAGE TemplateHaskell     #-}
-{-# LANGUAGE DataKinds           #-}
-{-# LANGUAGE NamedFieldPuns      #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE TypeFamilies        #-}
 
 {-# OPTIONS_GHC -Wno-missing-export-lists #-}
 
diff --git a/back/src/Guide/Api/Server.hs b/back/src/Guide/Api/Server.hs
index 29b054f..5ccec9e 100644
--- a/back/src/Guide/Api/Server.hs
+++ b/back/src/Guide/Api/Server.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE DataKinds         #-}
 {-# LANGUAGE FlexibleContexts  #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TypeApplications  #-}
-{-# LANGUAGE TypeOperators     #-}
-{-# LANGUAGE ScopedTypeVariables #-}
 
 module Guide.Api.Server
 (
diff --git a/back/src/Guide/Api/Types.hs b/back/src/Guide/Api/Types.hs
index c7a373b..ee471f9 100644
--- a/back/src/Guide/Api/Types.hs
+++ b/back/src/Guide/Api/Types.hs
@@ -1,12 +1,4 @@
-{-# LANGUAGE DataKinds             #-}
-{-# LANGUAGE TemplateHaskell       #-}
-{-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE FlexibleInstances     #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE OverloadedStrings     #-}
-{-# LANGUAGE TypeFamilies          #-}
-{-# LANGUAGE TypeOperators         #-}
-
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
diff --git a/back/src/Guide/Api/Utils.hs b/back/src/Guide/Api/Utils.hs
index a7909b7..07fbc02 100644
--- a/back/src/Guide/Api/Utils.hs
+++ b/back/src/Guide/Api/Utils.hs
@@ -1,11 +1,5 @@
-{-# LANGUAGE DataKinds            #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
-{-# LANGUAGE OverloadedStrings    #-}
-{-# LANGUAGE ScopedTypeVariables  #-}
-{-# LANGUAGE TypeApplications     #-}
-{-# LANGUAGE TypeFamilies         #-}
-{-# LANGUAGE TypeOperators        #-}
 {-# LANGUAGE UndecidableInstances #-}
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
diff --git a/back/src/Guide/App.hs b/back/src/Guide/App.hs
index e1e3a27..c2bda49 100644
--- a/back/src/Guide/App.hs
+++ b/back/src/Guide/App.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE ConstraintKinds #-}
-{-# LANGUAGE TypeFamilies    #-}
-
 {-# OPTIONS_GHC -Wno-missing-export-lists #-}
 
 -- | App module defines types used by the Spock framework.
diff --git a/back/src/Guide/Archival.hs b/back/src/Guide/Archival.hs
index 2c206ef..d759808 100644
--- a/back/src/Guide/Archival.hs
+++ b/back/src/Guide/Archival.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TypeApplications  #-}
-
-
 -- | Methods for working with archive.org. Right now the admin interface
 -- provides a list of broken links together with links to their archived
 -- copies; in the future we might add automatic archival and automatic link
diff --git a/back/src/Guide/Cli.hs b/back/src/Guide/Cli.hs
index 7ffb907..590d2ca 100644
--- a/back/src/Guide/Cli.hs
+++ b/back/src/Guide/Cli.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell   #-}
-
 -- | Guide's command line interface.
 --
 -- Run @guide --help@ to see available commands.
diff --git a/back/src/Guide/Config.hs b/back/src/Guide/Config.hs
index e367379..0ca3baf 100644
--- a/back/src/Guide/Config.hs
+++ b/back/src/Guide/Config.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell #-}
-
 -- | Server config. For instance, the admin password is stored here, as well
 -- as the base url (for correct link generation in feeds).
 module Guide.Config
diff --git a/back/src/Guide/Database/Connection.hs b/back/src/Guide/Database/Connection.hs
index 2d15d67..72164ff 100644
--- a/back/src/Guide/Database/Connection.hs
+++ b/back/src/Guide/Database/Connection.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-
-
 -- | Connect to the Guide database.
 module Guide.Database.Connection
        ( connect
diff --git a/back/src/Guide/Database/Queries/Delete.hs b/back/src/Guide/Database/Queries/Delete.hs
index f76ca04..6049940 100644
--- a/back/src/Guide/Database/Queries/Delete.hs
+++ b/back/src/Guide/Database/Queries/Delete.hs
@@ -1,8 +1,3 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE OverloadedLabels  #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeOperators     #-}
-
 -- | Delete queries.
 module Guide.Database.Queries.Delete
 (
diff --git a/back/src/Guide/Database/Queries/Insert.hs b/back/src/Guide/Database/Queries/Insert.hs
index c8f09d6..dedb0c8 100644
--- a/back/src/Guide/Database/Queries/Insert.hs
+++ b/back/src/Guide/Database/Queries/Insert.hs
@@ -1,9 +1,3 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE OverloadedLabels  #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeOperators     #-}
-
 -- | Insert queries.
 module Guide.Database.Queries.Insert
 (
diff --git a/back/src/Guide/Database/Queries/Select.hs b/back/src/Guide/Database/Queries/Select.hs
index 235a963..8eee6d5 100644
--- a/back/src/Guide/Database/Queries/Select.hs
+++ b/back/src/Guide/Database/Queries/Select.hs
@@ -1,8 +1,4 @@
 {-# LANGUAGE ApplicativeDo     #-}
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE OverloadedLabels  #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeOperators     #-}
 
 
 -- | Read-only database queries.
diff --git a/back/src/Guide/Database/Queries/Update.hs b/back/src/Guide/Database/Queries/Update.hs
index 27903e1..bab577f 100644
--- a/back/src/Guide/Database/Queries/Update.hs
+++ b/back/src/Guide/Database/Queries/Update.hs
@@ -1,11 +1,3 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TemplateHaskell   #-}
-{-# LANGUAGE OverloadedLabels  #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeOperators     #-}
-
--- | Update queries.
 module Guide.Database.Queries.Update
 (
   -- * Category
diff --git a/back/src/Guide/Database/Schema.hs b/back/src/Guide/Database/Schema.hs
index 9bb45e6..d889807 100644
--- a/back/src/Guide/Database/Schema.hs
+++ b/back/src/Guide/Database/Schema.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes       #-}
-
-
 -- | Schemas to create table for guide database
 module Guide.Database.Schema
 (
diff --git a/back/src/Guide/Database/Types.hs b/back/src/Guide/Database/Types.hs
index 828514b..e4bfcd7 100644
--- a/back/src/Guide/Database/Types.hs
+++ b/back/src/Guide/Database/Types.hs
@@ -1,10 +1,3 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TemplateHaskell   #-}
-{-# LANGUAGE OverloadedLabels  #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeOperators     #-}
-
 -- | Types for postgres database
 module Guide.Database.Types
        (
diff --git a/back/src/Guide/Database/Utils.hs b/back/src/Guide/Database/Utils.hs
index 1a21261..49f4b9a 100644
--- a/back/src/Guide/Database/Utils.hs
+++ b/back/src/Guide/Database/Utils.hs
@@ -1,12 +1,7 @@
 {-# LANGUAGE MonoLocalBinds #-}
 {-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE DefaultSignatures #-}
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE OverloadedLabels #-}
-{-# LANGUAGE TemplateHaskell #-}
 
 -- | Utilities for working with Postgres.
 module Guide.Database.Utils
diff --git a/back/src/Guide/Diff.hs b/back/src/Guide/Diff.hs
index 2a7c065..050876a 100644
--- a/back/src/Guide/Diff.hs
+++ b/back/src/Guide/Diff.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell   #-}
-
-
 -- | Diff- and merge-related things.
 module Guide.Diff
 (
diff --git a/back/src/Guide/Diff/Tokenize.hs b/back/src/Guide/Diff/Tokenize.hs
index f234245..240c6a0 100644
--- a/back/src/Guide/Diff/Tokenize.hs
+++ b/back/src/Guide/Diff/Tokenize.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE PatternSynonyms   #-}
-
-
 -- | Prepare text for diffing or merging by breaking it into tokens (like
 -- links or Markdown elements).
 module Guide.Diff.Tokenize
diff --git a/back/src/Guide/Handlers.hs b/back/src/Guide/Handlers.hs
index d1f6060..cfbc344 100644
--- a/back/src/Guide/Handlers.hs
+++ b/back/src/Guide/Handlers.hs
@@ -1,7 +1,4 @@
 {-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilies        #-}
 
 -- | All rest API handlers.
 module Guide.Handlers
diff --git a/back/src/Guide/JS.hs b/back/src/Guide/JS.hs
index eb33261..cac6bf4 100644
--- a/back/src/Guide/JS.hs
+++ b/back/src/Guide/JS.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE BangPatterns               #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE QuasiQuotes                #-}
 
 {-# OPTIONS_GHC -Wno-missing-export-lists #-}
 
diff --git a/back/src/Guide/Logger/Functions.hs b/back/src/Guide/Logger/Functions.hs
index 4c7d3cb..886534a 100644
--- a/back/src/Guide/Logger/Functions.hs
+++ b/back/src/Guide/Logger/Functions.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE FlexibleContexts    #-}
 
 module Guide.Logger.Functions
diff --git a/back/src/Guide/Logger/Run.hs b/back/src/Guide/Logger/Run.hs
index 5c8d6c3..f6790c0 100644
--- a/back/src/Guide/Logger/Run.hs
+++ b/back/src/Guide/Logger/Run.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE FlexibleContexts    #-}
 
 module Guide.Logger.Run
diff --git a/back/src/Guide/Logger/Types.hs b/back/src/Guide/Logger/Types.hs
index fecebf8..690e097 100644
--- a/back/src/Guide/Logger/Types.hs
+++ b/back/src/Guide/Logger/Types.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE StandaloneDeriving #-}
-
 {-# OPTIONS_GHC -fno-warn-orphans #-} -- for "instance Read Df1.Level"
 
 -- | The logger monad and associated types.
diff --git a/back/src/Guide/Main.hs b/back/src/Guide/Main.hs
index 6f7fcff..6c9aaed 100644
--- a/back/src/Guide/Main.hs
+++ b/back/src/Guide/Main.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE DataKinds           #-}
 {-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilies        #-}
-{-# LANGUAGE TypeOperators       #-}
 
 -- | Description : The main module that starts the server.
 module Guide.Main
diff --git a/back/src/Guide/Markdown.hs b/back/src/Guide/Markdown.hs
index f671767..acdb206 100644
--- a/back/src/Guide/Markdown.hs
+++ b/back/src/Guide/Markdown.hs
@@ -1,9 +1,5 @@
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE FlexibleContexts   #-}
 {-# LANGUAGE FlexibleInstances  #-}
-{-# LANGUAGE OverloadedStrings  #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE TemplateHaskell    #-}
 
 
 -- | Everything concerning rendering and processing Markdown.
diff --git a/back/src/Guide/Matomo.hs b/back/src/Guide/Matomo.hs
index a79be68..a103d26 100644
--- a/back/src/Guide/Matomo.hs
+++ b/back/src/Guide/Matomo.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-
-
 -- | Functions for interacting with Matomo (<https://matomo.org/>, our web
 -- analytics).
 --
diff --git a/back/src/Guide/Routes.hs b/back/src/Guide/Routes.hs
index af97e4f..4a48183 100644
--- a/back/src/Guide/Routes.hs
+++ b/back/src/Guide/Routes.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-
 module Guide.Routes
 (
   addRoute,
diff --git a/back/src/Guide/ServerStuff.hs b/back/src/Guide/ServerStuff.hs
index f4582ac..3b5e759 100644
--- a/back/src/Guide/ServerStuff.hs
+++ b/back/src/Guide/ServerStuff.hs
@@ -1,7 +1,4 @@
-{-# LANGUAGE DataKinds         #-}
 {-# LANGUAGE FlexibleContexts  #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TypeFamilies      #-}
 
 
 -- | Spock state, functions for manipulating it, handler helpers, and so on.
diff --git a/back/src/Guide/Session.hs b/back/src/Guide/Session.hs
index 915251f..2e1bbd3 100644
--- a/back/src/Guide/Session.hs
+++ b/back/src/Guide/Session.hs
@@ -1,9 +1,4 @@
-{-# LANGUAGE DataKinds           #-}
 {-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE GADTs               #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilies        #-}
-{-# LANGUAGE TypeOperators       #-}
 
 module Guide.Session
 (
diff --git a/back/src/Guide/State.hs b/back/src/Guide/State.hs
index fbe355f..d12dc7b 100644
--- a/back/src/Guide/State.hs
+++ b/back/src/Guide/State.hs
@@ -1,10 +1,5 @@
 {-# LANGUAGE FlexibleContexts   #-}
 {-# LANGUAGE FlexibleInstances  #-}
-{-# LANGUAGE OverloadedStrings  #-}
-{-# LANGUAGE QuasiQuotes        #-}
-{-# LANGUAGE TypeFamilies       #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE TemplateHaskell    #-}
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
diff --git a/back/src/Guide/Types/Analytics.hs b/back/src/Guide/Types/Analytics.hs
index c121e52..73f66ad 100644
--- a/back/src/Guide/Types/Analytics.hs
+++ b/back/src/Guide/Types/Analytics.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE TypeFamilies    #-}
-{-# LANGUAGE TemplateHaskell #-}
-
-
 -- | Types for analytics.
 --
 --  * We collect information about 'Action's that users perform. An action
diff --git a/back/src/Guide/Types/Core.hs b/back/src/Guide/Types/Core.hs
index 461aa98..9ab7b55 100644
--- a/back/src/Guide/Types/Core.hs
+++ b/back/src/Guide/Types/Core.hs
@@ -1,11 +1,5 @@
-{-# LANGUAGE DeriveDataTypeable  #-}
 {-# LANGUAGE FlexibleContexts    #-}
 {-# LANGUAGE FlexibleInstances   #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE QuasiQuotes         #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeFamilies        #-}
-{-# LANGUAGE TemplateHaskell     #-}
 
 
 -- | Core types for content.
diff --git a/back/src/Guide/Types/Edit.hs b/back/src/Guide/Types/Edit.hs
index c914120..0219cb4 100644
--- a/back/src/Guide/Types/Edit.hs
+++ b/back/src/Guide/Types/Edit.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE TypeFamilies    #-}
-{-# LANGUAGE TemplateHaskell #-}
-
-
 -- | Types for edits.
 --
 -- Every content edit is associated with an 'Edit', which is stored in the
@@ -254,7 +250,7 @@ instance Migrate Edit_v8 where
       EditAddCategory_v8
         { editCategoryUid_v8 = editCategoryUid_v7 x
         , editCategoryTitle_v8 = editCategoryTitle_v7 x
-        , editCategoryGroup_v8 = toText "Miscellaneous"
+        , editCategoryGroup_v8 = "Miscellaneous"
         } |],
     CopyM "EditAddItem",
     CopyM "EditAddPro",
diff --git a/back/src/Guide/Types/Hue.hs b/back/src/Guide/Types/Hue.hs
index fee0785..fb4dcc7 100644
--- a/back/src/Guide/Types/Hue.hs
+++ b/back/src/Guide/Types/Hue.hs
@@ -1,9 +1,3 @@
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE OverloadedStrings  #-}
-{-# LANGUAGE TemplateHaskell    #-}
-{-# LANGUAGE TypeFamilies       #-}
-
-
 -- | Deprecated as of 2019-07-25.
 --
 -- TODO: remove after we have migrated from acid-state.
diff --git a/back/src/Guide/Types/Session.hs b/back/src/Guide/Types/Session.hs
index f11dcca..ff452f4 100644
--- a/back/src/Guide/Types/Session.hs
+++ b/back/src/Guide/Types/Session.hs
@@ -1,8 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TemplateHaskell   #-}
-{-# LANGUAGE TypeFamilies      #-}
-
-
 module Guide.Types.Session
 (
   GuideData (..),
diff --git a/back/src/Guide/Types/User.hs b/back/src/Guide/Types/User.hs
index 52ce01b..e27f063 100644
--- a/back/src/Guide/Types/User.hs
+++ b/back/src/Guide/Types/User.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE TypeFamilies       #-}
-{-# LANGUAGE TemplateHaskell    #-}
-
 -- | A type for users. Currently unused.
 module Guide.Types.User
 (
diff --git a/back/src/Guide/Utils.hs b/back/src/Guide/Utils.hs
index 3ab61c3..400e5a0 100644
--- a/back/src/Guide/Utils.hs
+++ b/back/src/Guide/Utils.hs
@@ -1,12 +1,6 @@
-{-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE QuasiQuotes                #-}
-{-# LANGUAGE ScopedTypeVariables        #-}
-{-# LANGUAGE TypeFamilies               #-}
-{-# LANGUAGE TemplateHaskell            #-}
 
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
diff --git a/back/src/Guide/Views.hs b/back/src/Guide/Views.hs
index 46ce1ea..afdaff2 100644
--- a/back/src/Guide/Views.hs
+++ b/back/src/Guide/Views.hs
@@ -1,8 +1,4 @@
 {-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE QuasiQuotes         #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeApplications    #-}
 
 
 -- | All views and all rendering logic.
diff --git a/back/src/Guide/Views/Auth/Login.hs b/back/src/Guide/Views/Auth/Login.hs
index 455a7d1..968df93 100644
--- a/back/src/Guide/Views/Auth/Login.hs
+++ b/back/src/Guide/Views/Auth/Login.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 {-# OPTIONS_GHC -Wno-missing-export-lists #-}
 
diff --git a/back/src/Guide/Views/Auth/Register.hs b/back/src/Guide/Views/Auth/Register.hs
index 3cc7ec9..3d22fdb 100644
--- a/back/src/Guide/Views/Auth/Register.hs
+++ b/back/src/Guide/Views/Auth/Register.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 {-# OPTIONS_GHC -Wno-name-shadowing #-}
 {-# OPTIONS_GHC -Wno-missing-export-lists #-}
diff --git a/back/src/Guide/Views/Category.hs b/back/src/Guide/Views/Category.hs
index f45c3d6..a636e00 100644
--- a/back/src/Guide/Views/Category.hs
+++ b/back/src/Guide/Views/Category.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE FlexibleContexts  #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 
 -- | Category rendering.
diff --git a/back/src/Guide/Views/Item.hs b/back/src/Guide/Views/Item.hs
index 39b9bec..9a7e61c 100644
--- a/back/src/Guide/Views/Item.hs
+++ b/back/src/Guide/Views/Item.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
-
-
 -- | Item rendering.
 --
 -- The main functions this module provides are 'renderItem' and
diff --git a/back/src/Guide/Views/Page.hs b/back/src/Guide/Views/Page.hs
index 3343317..0b66de4 100644
--- a/back/src/Guide/Views/Page.hs
+++ b/back/src/Guide/Views/Page.hs
@@ -1,8 +1,5 @@
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TemplateHaskell   #-}
 
 
 -- | Page rendering.
diff --git a/back/src/Guide/Views/Utils.hs b/back/src/Guide/Views/Utils.hs
index 66ba8a9..2f32672 100644
--- a/back/src/Guide/Views/Utils.hs
+++ b/back/src/Guide/Views/Utils.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE FlexibleContexts  #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 -- | Various HTML utils, Mustache utils, etc.
 module Guide.Views.Utils
diff --git a/back/src/Guide/Views/Utils/Input.hs b/back/src/Guide/Views/Utils/Input.hs
index a8be798..da655e3 100644
--- a/back/src/Guide/Views/Utils/Input.hs
+++ b/back/src/Guide/Views/Utils/Input.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
 -- | Lucid rendering for inputs and form fields.
diff --git a/back/src/Imports.hs b/back/src/Imports.hs
index ecc47bc..9977619 100644
--- a/back/src/Imports.hs
+++ b/back/src/Imports.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-
-
 -- | Imports used in the whole codebase. (All modules import this one
 -- instead of the "Prelude".)
 module Imports
@@ -48,7 +45,7 @@ import GHC.Stack as X (HasCallStack)
 
 -- Don't let HLint complain about Data.ByteString being imported as
 -- something other than "BS" (and so on for other modules)
-{-# ANN module "HLint: ignore Avoid restricted qualification" #-}
+{-# ANN module ("HLint: ignore Avoid restricted qualification" :: String) #-}
 
 -- | Short type for lazy ByteString
 type LByteString = BSL.ByteString
diff --git a/back/tests/ApiSpec.hs b/back/tests/ApiSpec.hs
index 61af43d..cc05b28 100644
--- a/back/tests/ApiSpec.hs
+++ b/back/tests/ApiSpec.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE NoImplicitPrelude #-}
-
 -- | Integration tests for new API methods.
 module ApiSpec (tests) where
 
diff --git a/back/tests/LogSpec.hs b/back/tests/LogSpec.hs
index 3c6d306..fae3318 100644
--- a/back/tests/LogSpec.hs
+++ b/back/tests/LogSpec.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE QuasiQuotes #-}
-
 -- | Tests for logging of errors.
 module LogSpec (tests) where
 
diff --git a/back/tests/Main.hs b/back/tests/Main.hs
index 5f2eaca..9497495 100644
--- a/back/tests/Main.hs
+++ b/back/tests/Main.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-
-
 module Main (main) where
 
 -- Shared imports
diff --git a/back/tests/MarkdownSpec.hs b/back/tests/MarkdownSpec.hs
index 116b5fb..36b28b5 100644
--- a/back/tests/MarkdownSpec.hs
+++ b/back/tests/MarkdownSpec.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-
 module MarkdownSpec (tests) where
 
 -- Shared imports
diff --git a/back/tests/MergeSpec.hs b/back/tests/MergeSpec.hs
index aad08c6..f9ed151 100644
--- a/back/tests/MergeSpec.hs
+++ b/back/tests/MergeSpec.hs
@@ -1,7 +1,3 @@
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-
 module MergeSpec (tests) where
 
 -- Shared imports
diff --git a/back/tests/Selenium.hs b/back/tests/Selenium.hs
index fb31a57..0b2d611 100644
--- a/back/tests/Selenium.hs
+++ b/back/tests/Selenium.hs
@@ -1,9 +1,5 @@
 {-# LANGUAGE FlexibleInstances   #-}
-{-# LANGUAGE GADTs               #-}
 {-# LANGUAGE IncoherentInstances #-}
-{-# LANGUAGE NoImplicitPrelude   #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE StandaloneDeriving  #-}
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}  -- for "instance MonadFail WD"
 
diff --git a/back/tests/WebSpec.hs b/back/tests/WebSpec.hs
index afc5744..e83c258 100644
--- a/back/tests/WebSpec.hs
+++ b/back/tests/WebSpec.hs
@@ -1,8 +1,5 @@
 {-# LANGUAGE IncoherentInstances #-}
 {-# LANGUAGE MonoLocalBinds      #-}
-{-# LANGUAGE NoImplicitPrelude   #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE ScopedTypeVariables #-}
 
 
 module WebSpec (tests) where