diff --git a/build.sbt b/build.sbt
index 6952419..1280a2a 100644
--- a/build.sbt
+++ b/build.sbt
@@ -10,8 +10,6 @@
 
 lazy val root = (project in file("."))
   .enablePlugins(SbtTwirl, ScalatraPlugin)
-  .settings(
-    )
 
 sourcesInBase := false
 organization := Organization
@@ -75,7 +73,14 @@
 )
 
 // Compiler settings
-scalacOptions := Seq("-deprecation", "-language:postfixOps", "-opt:l:method", "-feature")
+scalacOptions := Seq(
+  "-deprecation",
+  "-language:postfixOps",
+  "-opt:l:method",
+  "-feature",
+  "-Wunused:imports",
+  "-Wconf:cat=unused&src=twirl/.*:s,cat=unused&src=scala/gitbucket/core/model/[^/]+\\.scala:s"
+)
 compile / javacOptions ++= Seq("-target", "8", "-source", "8")
 Jetty / javaOptions += "-Dlogback.configurationFile=/logback-dev.xml"
 
diff --git a/src/main/scala/ScalatraBootstrap.scala b/src/main/scala/ScalatraBootstrap.scala
index f49e529..3938f96 100644
--- a/src/main/scala/ScalatraBootstrap.scala
+++ b/src/main/scala/ScalatraBootstrap.scala
@@ -2,7 +2,6 @@
 import javax.servlet._
 
 import gitbucket.core.controller.{ReleaseController, _}
-import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.service.SystemSettingsService
 import gitbucket.core.servlet._
 import gitbucket.core.util.Directory
diff --git a/src/main/scala/gitbucket/core/api/ApiPlugin.scala b/src/main/scala/gitbucket/core/api/ApiPlugin.scala
index d386556..77fcce7 100644
--- a/src/main/scala/gitbucket/core/api/ApiPlugin.scala
+++ b/src/main/scala/gitbucket/core/api/ApiPlugin.scala
@@ -1,6 +1,6 @@
 package gitbucket.core.api
 
-import gitbucket.core.plugin.{PluginRegistry, PluginInfo}
+import gitbucket.core.plugin.PluginInfo
 
 case class ApiPlugin(
   id: String,
diff --git a/src/main/scala/gitbucket/core/api/ApiWebhook.scala b/src/main/scala/gitbucket/core/api/ApiWebhook.scala
index 30a5f48..025b43b 100644
--- a/src/main/scala/gitbucket/core/api/ApiWebhook.scala
+++ b/src/main/scala/gitbucket/core/api/ApiWebhook.scala
@@ -1,8 +1,6 @@
 package gitbucket.core.api
 
-import gitbucket.core.model.Profile.{RepositoryWebHookEvents, RepositoryWebHooks}
 import gitbucket.core.model.{RepositoryWebHook, WebHook}
-import gitbucket.core.util.RepositoryName
 
 /**
  * https://docs.github.com/en/rest/reference/repos#webhooks
diff --git a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
index bdaf277..e03e045 100644
--- a/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositorySettingsController.scala
@@ -1,6 +1,6 @@
 package gitbucket.core.controller
 
-import java.time.{LocalDateTime, ZoneId, ZoneOffset}
+import java.time.{LocalDateTime, ZoneOffset}
 import java.util.Date
 
 import gitbucket.core.settings.html
diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index 453a677..3884798 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -40,8 +40,6 @@
 import org.scalatra._
 import org.scalatra.i18n.Messages
 
-import scala.collection.JavaConverters.iterableAsScalaIterableConverter
-
 class RepositoryViewerController
     extends RepositoryViewerControllerBase
     with RepositoryService
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiIssueCommentControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiIssueCommentControllerBase.scala
index e4ed393..9db7ae7 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiIssueCommentControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiIssueCommentControllerBase.scala
@@ -4,7 +4,7 @@
 import gitbucket.core.service._
 import gitbucket.core.util.Implicits._
 import gitbucket.core.util.{ReadableUsersAuthenticator, ReferrerAuthenticator, RepositoryName}
-import org.scalatra.{ActionResult, NoContent}
+import org.scalatra.ActionResult
 
 trait ApiIssueCommentControllerBase extends ControllerBase {
   self: AccountService
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala
index 8d6b735..b1eaf5f 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiIssueControllerBase.scala
@@ -5,7 +5,7 @@
 import gitbucket.core.service.{AccountService, IssueCreationService, IssuesService, MilestonesService}
 import gitbucket.core.service.IssuesService.IssueSearchCondition
 import gitbucket.core.service.PullRequestService.PullRequestLimit
-import gitbucket.core.util.{ReadableUsersAuthenticator, ReferrerAuthenticator, RepositoryName, UsersAuthenticator}
+import gitbucket.core.util.{ReadableUsersAuthenticator, ReferrerAuthenticator, RepositoryName}
 import gitbucket.core.util.Implicits._
 
 trait ApiIssueControllerBase extends ControllerBase {
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiOrganizationControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiOrganizationControllerBase.scala
index 7c63753..5e82ca7 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiOrganizationControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiOrganizationControllerBase.scala
@@ -1,5 +1,5 @@
 package gitbucket.core.controller.api
-import gitbucket.core.api.{ApiGroup, CreateAGroup, ApiRepository, ApiUser, JsonFormat}
+import gitbucket.core.api.{ApiGroup, CreateAGroup, JsonFormat}
 import gitbucket.core.controller.ControllerBase
 import gitbucket.core.service.{AccountService, RepositoryService}
 import gitbucket.core.util.Implicits._
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiReleaseControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiReleaseControllerBase.scala
index 7eecf54..e321962 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiReleaseControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiReleaseControllerBase.scala
@@ -1,5 +1,5 @@
 package gitbucket.core.controller.api
-import java.io.{ByteArrayInputStream, File}
+import java.io.File
 
 import gitbucket.core.api._
 import gitbucket.core.controller.ControllerBase
@@ -9,7 +9,7 @@
 import gitbucket.core.util.Implicits._
 import gitbucket.core.util.SyntaxSugars.defining
 import org.apache.commons.io.FileUtils
-import org.scalatra.{Created, NoContent}
+import org.scalatra.NoContent
 
 trait ApiReleaseControllerBase extends ControllerBase {
   self: AccountService with ReleaseService with ReferrerAuthenticator with WritableUsersAuthenticator =>
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
index 519568c..eb2b233 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
@@ -1,7 +1,6 @@
 package gitbucket.core.controller.api
 import gitbucket.core.api.{ApiContents, ApiError, CreateAFile, JsonFormat}
 import gitbucket.core.controller.ControllerBase
-import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.service.{RepositoryCommitFileService, RepositoryService}
 import gitbucket.core.util.Directory.getRepositoryDir
 import gitbucket.core.util.JGitUtil.{FileInfo, getContentFromId, getFileList}
diff --git a/src/main/scala/gitbucket/core/model/AccountWebHookEvent.scala b/src/main/scala/gitbucket/core/model/AccountWebHookEvent.scala
index d30eaa8..82d1dc3 100644
--- a/src/main/scala/gitbucket/core/model/AccountWebHookEvent.scala
+++ b/src/main/scala/gitbucket/core/model/AccountWebHookEvent.scala
@@ -1,8 +1,6 @@
 package gitbucket.core.model
 
-trait AccountWebHookEventComponent extends TemplateComponent {
-  self: Profile =>
-
+trait AccountWebHookEventComponent extends TemplateComponent { self: Profile =>
   import profile.api._
   import gitbucket.core.model.Profile.AccountWebHooks
 
diff --git a/src/main/scala/gitbucket/core/model/ReleaseAsset.scala b/src/main/scala/gitbucket/core/model/ReleaseAsset.scala
index 28ca2ca..93771ba 100644
--- a/src/main/scala/gitbucket/core/model/ReleaseAsset.scala
+++ b/src/main/scala/gitbucket/core/model/ReleaseAsset.scala
@@ -2,9 +2,7 @@
 
 import java.util.Date
 
-trait ReleaseAssetComponent extends TemplateComponent {
-  self: Profile =>
-
+trait ReleaseAssetComponent extends TemplateComponent { self: Profile =>
   import profile.api._
   import self._
 
diff --git a/src/main/scala/gitbucket/core/model/ReleaseTag.scala b/src/main/scala/gitbucket/core/model/ReleaseTag.scala
index 7101da1..86c514e 100644
--- a/src/main/scala/gitbucket/core/model/ReleaseTag.scala
+++ b/src/main/scala/gitbucket/core/model/ReleaseTag.scala
@@ -1,8 +1,6 @@
 package gitbucket.core.model
 
-trait ReleaseTagComponent extends TemplateComponent {
-  self: Profile =>
-
+trait ReleaseTagComponent extends TemplateComponent { self: Profile =>
   import profile.api._
   import self._
 
diff --git a/src/main/scala/gitbucket/core/service/ActivityService.scala b/src/main/scala/gitbucket/core/service/ActivityService.scala
index 24f5821..eec6c8e 100644
--- a/src/main/scala/gitbucket/core/service/ActivityService.scala
+++ b/src/main/scala/gitbucket/core/service/ActivityService.scala
@@ -1,8 +1,6 @@
 package gitbucket.core.service
 
 import gitbucket.core.model.Activity
-import gitbucket.core.util.JGitUtil
-import gitbucket.core.model.Profile._
 import gitbucket.core.util.Directory._
 import org.json4s._
 import org.json4s.jackson.Serialization
@@ -11,10 +9,8 @@
 import scala.util.Using
 import java.io.FileOutputStream
 import java.nio.charset.StandardCharsets
-import java.util.UUID
 
 import gitbucket.core.controller.Context
-import gitbucket.core.model.activity.BaseActivityInfo
 import org.apache.commons.io.input.ReversedLinesFileReader
 
 import scala.collection.mutable.ListBuffer
diff --git a/src/main/scala/gitbucket/core/service/IssuesService.scala b/src/main/scala/gitbucket/core/service/IssuesService.scala
index fb2088d..3fcd293 100644
--- a/src/main/scala/gitbucket/core/service/IssuesService.scala
+++ b/src/main/scala/gitbucket/core/service/IssuesService.scala
@@ -5,17 +5,7 @@
 import gitbucket.core.util.Implicits._
 import gitbucket.core.util.SyntaxSugars._
 import gitbucket.core.controller.Context
-import gitbucket.core.model.{
-  Account,
-  CommitState,
-  Issue,
-  IssueComment,
-  IssueLabel,
-  Label,
-  PullRequest,
-  Repository,
-  Role
-}
+import gitbucket.core.model.{Account, Issue, IssueComment, IssueLabel, Label, PullRequest, Repository, Role}
 import gitbucket.core.model.Profile._
 import gitbucket.core.model.Profile.profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
diff --git a/src/main/scala/gitbucket/core/service/PrioritiesService.scala b/src/main/scala/gitbucket/core/service/PrioritiesService.scala
index 22037e7..ba6e3f7 100644
--- a/src/main/scala/gitbucket/core/service/PrioritiesService.scala
+++ b/src/main/scala/gitbucket/core/service/PrioritiesService.scala
@@ -3,7 +3,6 @@
 import gitbucket.core.model.Priority
 import gitbucket.core.model.Profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
-import gitbucket.core.util.StringUtil
 
 trait PrioritiesService {
 
diff --git a/src/main/scala/gitbucket/core/service/RepositoryService.scala b/src/main/scala/gitbucket/core/service/RepositoryService.scala
index e836446..7fb0d27 100644
--- a/src/main/scala/gitbucket/core/service/RepositoryService.scala
+++ b/src/main/scala/gitbucket/core/service/RepositoryService.scala
@@ -12,7 +12,7 @@
 import gitbucket.core.util.JGitUtil.FileInfo
 import org.apache.commons.io.FileUtils
 import org.eclipse.jgit.api.Git
-import org.eclipse.jgit.lib.{Repository => _, _}
+import org.eclipse.jgit.lib.{Repository => _}
 import scala.util.Using
 
 trait RepositoryService {
diff --git a/src/main/scala/gitbucket/core/service/WebHookService.scala b/src/main/scala/gitbucket/core/service/WebHookService.scala
index 5c3a22f..182729b 100644
--- a/src/main/scala/gitbucket/core/service/WebHookService.scala
+++ b/src/main/scala/gitbucket/core/service/WebHookService.scala
@@ -3,7 +3,6 @@
 import fr.brouillard.oss.security.xhub.XHub
 import fr.brouillard.oss.security.xhub.XHub.{XHubConverter, XHubDigest}
 import gitbucket.core.api._
-import gitbucket.core.controller.Context
 import gitbucket.core.model.{
   Account,
   AccountWebHook,
diff --git a/src/main/scala/gitbucket/core/servlet/InitializeListener.scala b/src/main/scala/gitbucket/core/servlet/InitializeListener.scala
index ad2f6a6..44f03ef 100644
--- a/src/main/scala/gitbucket/core/servlet/InitializeListener.scala
+++ b/src/main/scala/gitbucket/core/servlet/InitializeListener.scala
@@ -2,7 +2,6 @@
 
 import java.io.{File, FileOutputStream}
 
-import com.typesafe.config.ConfigFactory
 import gitbucket.core.GitBucketCoreModule
 import gitbucket.core.plugin.PluginRegistry
 import gitbucket.core.service.SystemSettingsService
diff --git a/src/main/scala/gitbucket/core/servlet/PluginControllerFilter.scala b/src/main/scala/gitbucket/core/servlet/PluginControllerFilter.scala
index c515b64..d91822c 100644
--- a/src/main/scala/gitbucket/core/servlet/PluginControllerFilter.scala
+++ b/src/main/scala/gitbucket/core/servlet/PluginControllerFilter.scala
@@ -1,7 +1,6 @@
 package gitbucket.core.servlet
 
 import javax.servlet._
-import javax.servlet.http.HttpServletRequest
 
 import gitbucket.core.controller.ControllerBase
 import gitbucket.core.plugin.PluginRegistry
diff --git a/src/main/scala/gitbucket/core/ssh/GitCommand.scala b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
index f6a42cb..a1596ca 100644
--- a/src/main/scala/gitbucket/core/ssh/GitCommand.scala
+++ b/src/main/scala/gitbucket/core/ssh/GitCommand.scala
@@ -4,7 +4,7 @@
 import gitbucket.core.plugin.{GitRepositoryRouting, PluginRegistry}
 import gitbucket.core.service.{AccountService, DeployKeyService, RepositoryService, SystemSettingsService}
 import gitbucket.core.servlet.{CommitLogHook, Database}
-import gitbucket.core.util.{SyntaxSugars, Directory}
+import gitbucket.core.util.Directory
 import org.apache.sshd.server.{Environment, ExitCallback, SessionAware}
 import org.apache.sshd.server.command.{Command, CommandFactory}
 import org.apache.sshd.server.session.ServerSession
diff --git a/src/main/scala/gitbucket/core/ssh/SshServerListener.scala b/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
index d5e8397..ce4360e 100644
--- a/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
+++ b/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
@@ -1,6 +1,5 @@
 package gitbucket.core.ssh
 
-import java.io.File
 import java.util.concurrent.atomic.AtomicBoolean
 import javax.servlet.{ServletContextEvent, ServletContextListener}
 
diff --git a/src/main/scala/gitbucket/core/util/Authenticator.scala b/src/main/scala/gitbucket/core/util/Authenticator.scala
index 80659be..b9c6020 100644
--- a/src/main/scala/gitbucket/core/util/Authenticator.scala
+++ b/src/main/scala/gitbucket/core/util/Authenticator.scala
@@ -5,7 +5,6 @@
 import gitbucket.core.model.Role
 import RepositoryService.RepositoryInfo
 import Implicits._
-import SyntaxSugars._
 
 /**
  * Allows only oneself and administrators.
diff --git a/src/main/scala/gitbucket/core/util/HttpClientUtil.scala b/src/main/scala/gitbucket/core/util/HttpClientUtil.scala
index 3f0ba46..49d06b8 100644
--- a/src/main/scala/gitbucket/core/util/HttpClientUtil.scala
+++ b/src/main/scala/gitbucket/core/util/HttpClientUtil.scala
@@ -1,6 +1,6 @@
 package gitbucket.core.util
 
-import java.net.{InetAddress, URL}
+import java.net.InetAddress
 
 import gitbucket.core.service.SystemSettingsService
 import org.apache.commons.net.util.SubnetUtils
diff --git a/src/main/scala/gitbucket/core/util/StringUtil.scala b/src/main/scala/gitbucket/core/util/StringUtil.scala
index 7da4a87..2f58036 100644
--- a/src/main/scala/gitbucket/core/util/StringUtil.scala
+++ b/src/main/scala/gitbucket/core/util/StringUtil.scala
@@ -12,7 +12,6 @@
 import org.apache.commons.io.IOUtils
 
 import scala.util.control.Exception._
-import scala.util.matching.Regex.Match.unapply
 
 object StringUtil {
 
diff --git a/src/main/scala/gitbucket/core/util/TextAvatarUtil.scala b/src/main/scala/gitbucket/core/util/TextAvatarUtil.scala
index 0f6d7ce..26106b4 100644
--- a/src/main/scala/gitbucket/core/util/TextAvatarUtil.scala
+++ b/src/main/scala/gitbucket/core/util/TextAvatarUtil.scala
@@ -3,7 +3,7 @@
 import java.io.ByteArrayOutputStream
 import java.awt.image.BufferedImage
 import javax.imageio.ImageIO
-import java.awt.{Color, Font, Graphics2D, RenderingHints}
+import java.awt.{Color, Font, RenderingHints}
 import java.awt.font.{FontRenderContext, TextLayout}
 import java.awt.geom.AffineTransform
 
diff --git a/src/test/scala/gitbucket/core/service/CommitStatusServiceSpec.scala b/src/test/scala/gitbucket/core/service/CommitStatusServiceSpec.scala
index be03a06..fdf544f 100644
--- a/src/test/scala/gitbucket/core/service/CommitStatusServiceSpec.scala
+++ b/src/test/scala/gitbucket/core/service/CommitStatusServiceSpec.scala
@@ -2,7 +2,6 @@
 
 import gitbucket.core.model._
 import gitbucket.core.model.Profile._
-import gitbucket.core.model.Profile.profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
 import org.scalatest.funsuite.AnyFunSuite
 
diff --git a/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala b/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala
index e3a10c5..027f595 100644
--- a/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala
+++ b/src/test/scala/gitbucket/core/service/MergeServiceSpec.scala
@@ -21,7 +21,6 @@
 import gitbucket.core.model._
 import gitbucket.core.model.Profile._
 import gitbucket.core.model.Profile.profile.blockingApi._
-import gitbucket.core.service.WebHookService.WebHookPushPayload
 import org.eclipse.jetty.webapp.WebAppContext
 import org.eclipse.jetty.server.{Request, Server}
 import org.json4s.jackson.JsonMethods._