diff --git a/build.sbt b/build.sbt
index a97a5ee..2933078 100644
--- a/build.sbt
+++ b/build.sbt
@@ -4,20 +4,9 @@ organization := "org.codelibs.gitbucket"
 
 version := "1.2.1-SNAPSHOT"
 
-scalaVersion := "2.12.1"
+scalaVersion := "2.12.4"
 
-lazy val root = (project in file(".")).enablePlugins(SbtTwirl)
-
-resolvers ++= Seq(
-  Resolver.jcenterRepo
-)
-
-libraryDependencies ++= Seq(
-  "io.github.gitbucket" %% "gitbucket"        % "4.15.0" % "provided",
-  "com.typesafe.play"   %% "twirl-compiler"   % "1.3.0" % "provided",
-  "org.json4s"          %% "json4s-jackson"   % "3.5.0",
-  "javax.servlet"       % "javax.servlet-api" % "3.0.1" % "provided"
-)
+gitbucketVersion := "4.20.0"
 
 publishMavenStyle := true
 
diff --git a/project/build.properties b/project/build.properties
index b168a33..c4dc11b 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version = 0.13.13
+sbt.version = 1.1.0
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 340dc9d..44f4a0d 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,2 +1,2 @@
-addSbtPlugin("com.typesafe.sbt" % "sbt-twirl" % "1.3.0")
-addSbtPlugin("com.geirsson" % "sbt-scalafmt" % "0.5.6")
+addSbtPlugin("io.github.gitbucket" % "sbt-gitbucket-plugin" % "1.2.0")
+addSbtPlugin("com.geirsson" % "sbt-scalafmt" % "1.4.0")
diff --git a/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSearchController.scala b/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSearchController.scala
index 314f099..4ced58e 100644
--- a/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSearchController.scala
+++ b/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSearchController.scala
@@ -7,9 +7,6 @@ import org.codelibs.gitbucket.fess.html
 import gitbucket.core.util._
 import gitbucket.core.util.Implicits._
 
-import scala.reflect.ClassTag
-import scala.reflect.runtime.universe._
-
 class FessSearchController
     extends FessSearchControllerBase
     with FessSearchService
diff --git a/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSettingsController.scala b/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSettingsController.scala
index fa7df30..eaa8818 100644
--- a/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSettingsController.scala
+++ b/src/main/scala/org/codelibs/gitbucket/fess/controller/FessSettingsController.scala
@@ -2,8 +2,8 @@ package org.codelibs.gitbucket.fess.controller
 
 import gitbucket.core.controller.ControllerBase
 import gitbucket.core.util.AdminAuthenticator
+import org.scalatra.forms._
 import org.codelibs.gitbucket.fess.html
-import io.github.gitbucket.scalatra.forms._
 import org.codelibs.gitbucket.fess.service.FessSettingsService
 import org.codelibs.gitbucket.fess.service.FessSettingsService._