diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c830988..2a59cac 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -28,6 +28,8 @@
         distribution: adopt
     - name: Run tests
       run: sbt scalafmtSbtCheck scalafmtCheck test:scalafmtCheck test
+    - name: Scala 3
+      run: sbt '++ 3.0.1-RC1!' update # TODO
     - name: Build executable
       run: sbt executable
     - name: Upload artifacts
diff --git a/build.sbt b/build.sbt
index dfff5ba..74d9415 100644
--- a/build.sbt
+++ b/build.sbt
@@ -31,10 +31,10 @@
 libraryDependencies ++= Seq(
   "org.eclipse.jgit"                % "org.eclipse.jgit.http.server" % JgitVersion,
   "org.eclipse.jgit"                % "org.eclipse.jgit.archive"     % JgitVersion,
-  "org.scalatra"                    %% "scalatra"                    % ScalatraVersion,
-  "org.scalatra"                    %% "scalatra-json"               % ScalatraVersion,
-  "org.scalatra"                    %% "scalatra-forms"              % ScalatraVersion,
-  "org.json4s"                      %% "json4s-jackson"              % "3.6.11",
+  "org.scalatra"                    %% "scalatra"                    % ScalatraVersion cross CrossVersion.for3Use2_13,
+  "org.scalatra"                    %% "scalatra-json"               % ScalatraVersion cross CrossVersion.for3Use2_13,
+  "org.scalatra"                    %% "scalatra-forms"              % ScalatraVersion cross CrossVersion.for3Use2_13,
+  "org.json4s"                      %% "json4s-jackson"              % "3.6.11" cross CrossVersion.for3Use2_13,
   "commons-io"                      % "commons-io"                   % "2.9.0",
   "io.github.gitbucket"             % "solidbase"                    % "1.0.3",
   "io.github.gitbucket"             % "markedj"                      % "1.0.16",
@@ -44,7 +44,7 @@
   "org.apache.httpcomponents"       % "httpclient"                   % "4.5.13",
   "org.apache.sshd"                 % "apache-sshd"                  % "2.1.0" exclude ("org.slf4j", "slf4j-jdk14") exclude ("org.apache.sshd", "sshd-mina") exclude ("org.apache.sshd", "sshd-netty"),
   "org.apache.tika"                 % "tika-core"                    % "1.26",
-  "com.github.takezoe"              %% "blocking-slick-32"           % "0.0.12",
+  "com.github.takezoe"              %% "blocking-slick-32"           % "0.0.12" cross CrossVersion.for3Use2_13,
   "com.novell.ldap"                 % "jldap"                        % "2009-10-07",
   "com.h2database"                  % "h2"                           % "1.4.199",
   "org.mariadb.jdbc"                % "mariadb-java-client"          % "2.7.3",
@@ -61,7 +61,7 @@
   "org.eclipse.jetty"               % "jetty-webapp"                 % JettyVersion % "provided",
   "javax.servlet"                   % "javax.servlet-api"            % "3.1.0" % "provided",
   "junit"                           % "junit"                        % "4.13.2" % "test",
-  "org.scalatra"                    %% "scalatra-scalatest"          % ScalatraVersion % "test",
+  "org.scalatra"                    %% "scalatra-scalatest"          % ScalatraVersion % "test" cross CrossVersion.for3Use2_13,
   "org.mockito"                     % "mockito-core"                 % "3.11.0" % "test",
   "com.dimafeng"                    %% "testcontainers-scala"        % "0.39.5" % "test",
   "org.testcontainers"              % "mysql"                        % "1.15.3" % "test",
@@ -72,6 +72,15 @@
   "org.kohsuke"                     % "github-api"                   % "1.130" % "test"
 )
 
+libraryDependencies ~= {
+  _.map {
+    case x if x.name == "twirl-api" =>
+      x cross CrossVersion.for3Use2_13
+    case x =>
+      x
+  }
+}
+
 // Compiler settings
 scalacOptions := Seq(
   "-deprecation",