diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e147c7de7d..7b92d619ce 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-22.04]
-        scala: [2.13]
+        scala: [2.13, 3]
         java: [temurin@21, temurin@17, temurin@11]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
@@ -177,6 +177,16 @@ jobs:
           tar xf targets.tar
           rm targets.tar
 
+      - name: Download target directories (3)
+        uses: actions/download-artifact@v4
+        with:
+          name: target-${{ matrix.os }}-${{ matrix.java }}-3
+
+      - name: Inflate target directories (3)
+        run: |
+          tar xf targets.tar
+          rm targets.tar
+
       - name: Publish JARs
         env:
           PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
diff --git a/.mergify.yml b/.mergify.yml
index dbcbb8e87f..86c8a5f779 100644
--- a/.mergify.yml
+++ b/.mergify.yml
@@ -24,6 +24,9 @@ pull_request_rules:
   - status-success=Test (ubuntu-22.04, 2.13, temurin@21)
   - status-success=Test (ubuntu-22.04, 2.13, temurin@17)
   - status-success=Test (ubuntu-22.04, 2.13, temurin@11)
+  - status-success=Test (ubuntu-22.04, 3, temurin@21)
+  - status-success=Test (ubuntu-22.04, 3, temurin@17)
+  - status-success=Test (ubuntu-22.04, 3, temurin@11)
   actions:
     merge:
       method: merge
diff --git a/build.sbt b/build.sbt
index 7cb6d29359..5304ef626a 100644
--- a/build.sbt
+++ b/build.sbt
@@ -21,10 +21,11 @@ val moduleCrossPlatformMatrix: Map[String, List[Platform]] = Map(
 )
 
 val Scala213 = "2.13.15"
+val Scala3 = "3.3.4"
 
 /// sbt-typelevel configuration
 
-ThisBuild / crossScalaVersions := Seq(Scala213)
+ThisBuild / crossScalaVersions := Seq(Scala213, Scala3)
 ThisBuild / githubWorkflowTargetTags ++= Seq("v*")
 ThisBuild / githubWorkflowPublishTargetBranches := Seq(
   RefPredicate.Equals(Ref.Branch(mainBranch)),
@@ -109,6 +110,7 @@ lazy val benchmark = myCrossProject("benchmark")
   .enablePlugins(JmhPlugin)
   .settings(noPublishSettings)
   .settings(
+    crossScalaVersions := Seq(Scala213, Scala3),
     scalacOptions -= "-Wnonunit-statement",
     coverageEnabled := false,
     unusedCompileDependencies := Set.empty
@@ -118,6 +120,7 @@ lazy val core = myCrossProject("core")
   .enablePlugins(BuildInfoPlugin, JavaAppPackaging, DockerPlugin)
   .settings(dockerSettings)
   .settings(
+    crossScalaVersions := Seq(Scala213, Scala3),
     libraryDependencies ++= Seq(
       Dependencies.bcprovJdk15to18,
       Dependencies.betterFiles,
@@ -129,8 +132,8 @@ lazy val core = myCrossProject("core")
       Dependencies.circeParser,
       Dependencies.circeRefined,
       Dependencies.commonsIo,
-      Dependencies.coursierCore,
-      Dependencies.coursierSbtMaven,
+      Dependencies.coursierCore.cross(CrossVersion.for3Use2_13),
+      Dependencies.coursierSbtMaven.cross(CrossVersion.for3Use2_13),
       Dependencies.cron4sCore,
       Dependencies.decline,
       Dependencies.fs2Core,
@@ -158,6 +161,9 @@ lazy val core = myCrossProject("core")
       Dependencies.refinedScalacheck % Test,
       Dependencies.scalacheck % Test
     ),
+    // Workaround for https://github.com/cb372/sbt-explicit-dependencies/issues/117
+    unusedCompileDependenciesFilter -=
+      moduleFilter(organization = Dependencies.coursierCore.organization),
     assembly / test := {},
     assembly / assemblyMergeStrategy := {
       case PathList("META-INF", "versions", "9", "module-info.class") =>
@@ -244,6 +250,7 @@ lazy val docs = myCrossProject("docs")
   .enablePlugins(MdocPlugin)
   .settings(noPublishSettings)
   .settings(
+    scalacOptions += "-Ytasty-reader",
     mdocIn := baseDirectory.value / ".." / "mdoc",
     mdocOut := (LocalRootProject / baseDirectory).value / "docs",
     mdocVariables := Map(
diff --git a/modules/core/src/main/scala/org/scalasteward/core/client/ClientConfiguration.scala b/modules/core/src/main/scala/org/scalasteward/core/client/ClientConfiguration.scala
index bc28926141..1d330fd242 100644
--- a/modules/core/src/main/scala/org/scalasteward/core/client/ClientConfiguration.scala
+++ b/modules/core/src/main/scala/org/scalasteward/core/client/ClientConfiguration.scala
@@ -50,6 +50,7 @@ object ClientConfiguration {
           val params = javax.net.ssl.SSLContext.getDefault().getDefaultSSLParameters()
           params.setProtocols(params.getProtocols().filter(_ != "TLSv1.3"))
           builder.sslParameters(params)
+          ()
         }
 
         builder.executor(exec)
diff --git a/modules/core/src/main/scala/org/scalasteward/core/forge/github/GitHubAuthAlg.scala b/modules/core/src/main/scala/org/scalasteward/core/forge/github/GitHubAuthAlg.scala
index 71894276da..360111d232 100644
--- a/modules/core/src/main/scala/org/scalasteward/core/forge/github/GitHubAuthAlg.scala
+++ b/modules/core/src/main/scala/org/scalasteward/core/forge/github/GitHubAuthAlg.scala
@@ -152,6 +152,7 @@ final class GitHubAuthAlg[F[_]](
         val expMillis = nowMillis + ttlMillis
         val exp = new Date(expMillis)
         builder.expiration(exp)
+        ()
       }
       builder.compact()
     }
diff --git a/modules/core/src/main/scala/org/scalasteward/core/nurture/UpdateInfoUrlFinder.scala b/modules/core/src/main/scala/org/scalasteward/core/nurture/UpdateInfoUrlFinder.scala
index bebf18a975..4d4009e2ce 100644
--- a/modules/core/src/main/scala/org/scalasteward/core/nurture/UpdateInfoUrlFinder.scala
+++ b/modules/core/src/main/scala/org/scalasteward/core/nurture/UpdateInfoUrlFinder.scala
@@ -89,8 +89,8 @@ object UpdateInfoUrlFinder {
       fileNames.map(f => wrap(forgeRepo.fileUrlFor(f)))
 
     gitHubReleaseNotesFor(forgeRepo, update.nextVersion) ++
-      customUrls(CustomReleaseNotes, possibleReleaseNotesFilenames) ++
-      customUrls(CustomChangelog, possibleChangelogFilenames) ++
+      customUrls(CustomReleaseNotes.apply, possibleReleaseNotesFilenames) ++
+      customUrls(CustomChangelog.apply, possibleChangelogFilenames) ++
       possibleVersionDiffs(forgeRepo, update)
   }
 
diff --git a/modules/core/src/main/scala/org/scalasteward/core/repoconfig/PullRequestFrequency.scala b/modules/core/src/main/scala/org/scalasteward/core/repoconfig/PullRequestFrequency.scala
index 57ddbcdefd..0761dfd8e9 100644
--- a/modules/core/src/main/scala/org/scalasteward/core/repoconfig/PullRequestFrequency.scala
+++ b/modules/core/src/main/scala/org/scalasteward/core/repoconfig/PullRequestFrequency.scala
@@ -19,6 +19,7 @@ package org.scalasteward.core.repoconfig
 import cats.Eq
 import cats.syntax.all._
 import cron4s.lib.javatime._
+import cron4s.syntax.cron._
 import io.circe.{Decoder, Encoder}
 import org.scalasteward.core.repoconfig.PullRequestFrequency._
 import org.scalasteward.core.util.Timestamp
diff --git a/modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala b/modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala
index 624ae2112e..eacdcc9a3a 100644
--- a/modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala
+++ b/modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala
@@ -26,7 +26,6 @@ import org.scalasteward.core.buildtool.maven.pomXmlName
 import org.scalasteward.core.buildtool.mill.MillAlg
 import org.scalasteward.core.buildtool.sbt.buildPropertiesName
 import org.scalasteward.core.data.{GroupId, Update}
-import org.scalasteward.core.repoconfig.UpdatesConfig.defaultLimit
 import org.scalasteward.core.scalafmt.scalafmtConfName
 import org.scalasteward.core.update.FilterAlg.{
   FilterResult,
@@ -42,7 +41,7 @@ final case class UpdatesConfig(
     private val allowPreReleases: Option[List[UpdatePattern]] = None,
     private val ignore: Option[List[UpdatePattern]] = None,
     private val retracted: Option[List[RetractedArtifact]] = None,
-    limit: Option[NonNegInt] = defaultLimit,
+    limit: Option[NonNegInt] = UpdatesConfig.defaultLimit,
     private val fileExtensions: Option[List[String]] = None
 ) {
   private[repoconfig] def pinOrDefault: List[UpdatePattern] =
diff --git a/modules/core/src/test/scala/org/scalasteward/core/BuiltinConfigFilesTest.scala b/modules/core/src/test/scala/org/scalasteward/core/BuiltinConfigFilesTest.scala
index 35fcb58361..644bf0a513 100644
--- a/modules/core/src/test/scala/org/scalasteward/core/BuiltinConfigFilesTest.scala
+++ b/modules/core/src/test/scala/org/scalasteward/core/BuiltinConfigFilesTest.scala
@@ -12,6 +12,7 @@ import org.scalasteward.core.mock.MockContext.context.{
   scalafixMigrationsLoader
 }
 import org.scalasteward.core.mock.MockContext.mockState
+import org.scalasteward.core.mock.MockEffOps
 import org.scalasteward.core.repoconfig.RepoConfigLoader
 import org.scalasteward.core.update.artifact.ArtifactMigrationsLoader
 import scala.util.{Failure, Success, Try}
diff --git a/modules/core/src/test/scala/org/scalasteward/core/util/uriTest.scala b/modules/core/src/test/scala/org/scalasteward/core/util/uriTest.scala
index 920509f724..01fb2a24eb 100644
--- a/modules/core/src/test/scala/org/scalasteward/core/util/uriTest.scala
+++ b/modules/core/src/test/scala/org/scalasteward/core/util/uriTest.scala
@@ -3,13 +3,13 @@ package org.scalasteward.core.util
 import munit.FunSuite
 import org.http4s.Uri.UserInfo
 import org.http4s.syntax.literals._
+import org.scalasteward.core.util
 
 class uriTest extends FunSuite {
   test("withUserInfo") {
     val url = uri"https://api.github.com/repos/"
-    assertEquals(
-      uri.withUserInfo.replace(UserInfo("user", Some("pass")))(url).toString,
-      "https://user:pass@api.github.com/repos/"
-    )
+    val obtained = util.uri.withUserInfo.replace(UserInfo("user", Some("pass")))(url).toString
+    val expected = "https://user:pass@api.github.com/repos/"
+    assertEquals(obtained, expected)
   }
 }