diff --git a/contributing-docs/05_scripted_tests.md b/contributing-docs/05_scripted_tests.md
index 1d6d12b43..26ee9d2a2 100644
--- a/contributing-docs/05_scripted_tests.md
+++ b/contributing-docs/05_scripted_tests.md
@@ -28,7 +28,7 @@ Create an initial build in `something`. Like a real build using sbt. I'm sure yo
 
 ```scala
 name := "foo"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 ```
 
 I also have `Hello.scala`:
@@ -107,7 +107,7 @@ import scala.sys.process.Process
 lazy val check = taskKey[Unit]("check")
 
 name := "foo"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 check := {
   val pkg = (Compile / packageBin).value
   val conv = fileConverter.value
diff --git a/launcher-package/citest/build.sbt b/launcher-package/citest/build.sbt
index db7cfff7d..9afef5b42 100644
--- a/launcher-package/citest/build.sbt
+++ b/launcher-package/citest/build.sbt
@@ -3,7 +3,7 @@ lazy val check2 = taskKey[Unit]("")
 
 lazy val root = (project in file("."))
   .settings(
-    scalaVersion := "3.8.3",
+    scalaVersion := "3.8.4",
     name := "Hello",
     libraryDependencies += "com.eed3si9n.verify" %% "verify" % "1.0.0" % Test,
     testFrameworks += new TestFramework("verify.runner.Framework"),
diff --git a/launcher-package/citest2/build.sbt b/launcher-package/citest2/build.sbt
index e71bb07cc..90ebe88bc 100644
--- a/launcher-package/citest2/build.sbt
+++ b/launcher-package/citest2/build.sbt
@@ -1,5 +1,5 @@
 lazy val root = (project in file("."))
   .settings(
-    scalaVersion := "3.8.3",
+    scalaVersion := "3.8.4",
     name := "Hello",
   )
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index c89309736..235c5fad1 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -3,14 +3,14 @@ import Keys.*
 
 object Dependencies {
   // WARNING: Please Scala update versions in PluginCross.scala too
-  val scala3 = "3.8.3"
+  val scala3 = "3.8.4"
   val scala212 = "2.12.21"
   val baseScalaVersion = scala3
   def nightlyVersion: Option[String] =
     sys.env.get("BUILD_VERSION") orElse sys.props.get("sbt.build.version")
 
   // sbt modules
-  val ioVersion = nightlyVersion.getOrElse("1.12.0")
+  val ioVersion = nightlyVersion.getOrElse("1.12.1")
   val zincVersion = nightlyVersion.getOrElse("2.0.0-M18")
 
   private val sbtIO = "org.scala-sbt" %% "io" % ioVersion
diff --git a/sbt-app/src/sbt-test/cache/cached-compile/build.sbt b/sbt-app/src/sbt-test/cache/cached-compile/build.sbt
index ecfd9eb5b..5d5324e01 100644
--- a/sbt-app/src/sbt-test/cache/cached-compile/build.sbt
+++ b/sbt-app/src/sbt-test/cache/cached-compile/build.sbt
@@ -5,7 +5,7 @@ lazy val checkMiss = inputKey[Unit]("")
 
 Global / localCacheDirectory := baseDirectory.value / "diskcache"
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 checkMiss := {
   val expected: Int = (Space ~> NatBasic).parsed
   val s = streams.value
diff --git a/sbt-app/src/sbt-test/cache/cached-test/build.sbt b/sbt-app/src/sbt-test/cache/cached-test/build.sbt
index 497d46d69..e6867d953 100644
--- a/sbt-app/src/sbt-test/cache/cached-test/build.sbt
+++ b/sbt-app/src/sbt-test/cache/cached-test/build.sbt
@@ -5,7 +5,7 @@ lazy val verify = "com.eed3si9n.verify" %% "verify" % "1.0.0"
 
 Global / localCacheDirectory := baseDirectory.value / "diskcache"
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 libraryDependencies += verify % Test
 testFrameworks += new TestFramework("verify.runner.Framework")
 
diff --git a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-http/build.sbt b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-http/build.sbt
index d5b056e6d..05fc08ad0 100644
--- a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-http/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-http/build.sbt
@@ -3,7 +3,7 @@ ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-c
 name := "lib1"
 organization := "com.example"
 version := "0.1.0-SNAPSHOT"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 val publishRepoBase = settingKey[File]("Base directory for publish repo (HTTP server writes here)")
 publishRepoBase := baseDirectory.value / "repo"
diff --git a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-local/build.sbt b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-local/build.sbt
index fe670d2f8..86f2cdeba 100644
--- a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-local/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-local/build.sbt
@@ -3,7 +3,7 @@ ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-c
 name := "lib1"
 organization := "com.example"
 version := "0.1.0-SNAPSHOT"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 // Use a fixed path for local ivy repo to avoid sbt 2.x output sharding
 val ivyLocalBase = settingKey[File]("Local Ivy repository base")
diff --git a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven-http/build.sbt b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven-http/build.sbt
index b9763fb39..35524f841 100644
--- a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven-http/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven-http/build.sbt
@@ -1,7 +1,7 @@
 ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-cache"
 ThisBuild / organization := "com.example"
 ThisBuild / version := "0.1.0-SNAPSHOT"
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 val publishRepoBase = settingKey[File]("Base directory for Maven publish repo (HTTP server writes here)")
 ThisBuild / publishRepoBase := (ThisBuild / baseDirectory).value / "repo"
diff --git a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven/build.sbt b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven/build.sbt
index 03566e157..f7033537f 100644
--- a/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven/build.sbt
@@ -3,7 +3,7 @@ ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-c
 name := "lib1"
 organization := "com.example"
 version := "0.1.0-SNAPSHOT"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 publishMavenStyle := true
 val publishRepoBase = settingKey[File]("Base directory for Maven publish repo")
diff --git a/sbt-app/src/sbt-test/dependency-management/ivyless-publish/build.sbt b/sbt-app/src/sbt-test/dependency-management/ivyless-publish/build.sbt
index 23d6e97bf..7bb4065cf 100644
--- a/sbt-app/src/sbt-test/dependency-management/ivyless-publish/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/ivyless-publish/build.sbt
@@ -3,7 +3,7 @@ ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-c
 name := "lib1"
 organization := "com.example"
 version := "0.1.0-SNAPSHOT"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 // Publish to a file repo (tests ivyless publish without HTTP server)
 val publishRepoBase = settingKey[File]("Base directory for publish repo")
diff --git a/sbt-app/src/sbt-test/dependency-management/platform-artifact-name/build.sbt b/sbt-app/src/sbt-test/dependency-management/platform-artifact-name/build.sbt
index 4f5547891..120a0398e 100644
--- a/sbt-app/src/sbt-test/dependency-management/platform-artifact-name/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/platform-artifact-name/build.sbt
@@ -1,7 +1,7 @@
 ThisBuild / organization := "com.example"
 name := "testproj"
 version := "0.1.0-SNAPSHOT"
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 platform := "native0.5"
 crossVersion := CrossVersion.binary
diff --git a/sbt-app/src/sbt-test/dependency-management/platform-publish/build.sbt b/sbt-app/src/sbt-test/dependency-management/platform-publish/build.sbt
index 379a3fe74..7ad0b638b 100644
--- a/sbt-app/src/sbt-test/dependency-management/platform-publish/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/platform-publish/build.sbt
@@ -3,7 +3,7 @@
 
 ThisBuild / organization := "com.example"
 ThisBuild / version := "0.1.0"
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 ThisBuild / csrCacheDirectory := (ThisBuild / baseDirectory).value / "coursier-cache"
 
 lazy val mavenRepo = settingKey[File]("shared local Maven repo for the consume round-trip")
diff --git a/sbt-app/src/sbt-test/dependency-management/stdlib-3.8/build.sbt b/sbt-app/src/sbt-test/dependency-management/stdlib-3.8/build.sbt
index 491ca3d5a..cde36b6d9 100644
--- a/sbt-app/src/sbt-test/dependency-management/stdlib-3.8/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/stdlib-3.8/build.sbt
@@ -1,6 +1,6 @@
 lazy val a = project
   .settings(
-    scalaVersion := "3.8.3"
+    scalaVersion := "3.8.4"
   )
 
 // (b / update) sbt.librarymanagement.ResolveException: Error downloading org.scala-lang:scala-reflect:3.8.3
diff --git a/sbt-app/src/sbt-test/nio/clean-symlinks/build.sbt b/sbt-app/src/sbt-test/nio/clean-symlinks/build.sbt
index 3b5cd245e..a03570948 100644
--- a/sbt-app/src/sbt-test/nio/clean-symlinks/build.sbt
+++ b/sbt-app/src/sbt-test/nio/clean-symlinks/build.sbt
@@ -2,7 +2,7 @@ import java.nio.file.Files
 
 name := "clean-symlinks-test"
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 TaskKey[Unit]("createSymlinkedDirectory") := {
   IO.createDirectory(target.value)
diff --git a/sbt-app/src/sbt-test/nio/clean-symlinks/test b/sbt-app/src/sbt-test/nio/clean-symlinks/test
index 51fa24df1..0754f14ad 100644
--- a/sbt-app/src/sbt-test/nio/clean-symlinks/test
+++ b/sbt-app/src/sbt-test/nio/clean-symlinks/test
@@ -1,9 +1,9 @@
 > createSymlinkedDirectory
 
-$ exists target/out/jvm/scala-3.8.3/clean-symlinks-test/foo/bar
+$ exists target/**/clean-symlinks-test/foo/bar
 $ exists foo/bar
 
 > clean
 
-$ absent target/out/jvm/scala-3.8.3/clean-symlinks-test/foo
+$ absent target/**/clean-symlinks-test/foo
 $ exists foo/bar
diff --git a/sbt-app/src/sbt-test/plugins/auto-plugins-minimal/build.sbt b/sbt-app/src/sbt-test/plugins/auto-plugins-minimal/build.sbt
index 69074af7c..42b26b739 100644
--- a/sbt-app/src/sbt-test/plugins/auto-plugins-minimal/build.sbt
+++ b/sbt-app/src/sbt-test/plugins/auto-plugins-minimal/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 organization := "com.example"
 
diff --git a/sbt-app/src/sbt-test/plugins/pgp/build.sbt b/sbt-app/src/sbt-test/plugins/pgp/build.sbt
index fa9609bc6..e48f8ce4b 100644
--- a/sbt-app/src/sbt-test/plugins/pgp/build.sbt
+++ b/sbt-app/src/sbt-test/plugins/pgp/build.sbt
@@ -1,2 +1,2 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 publishLocal := {}
diff --git a/sbt-app/src/sbt-test/plugins/plugin-cross/build.sbt b/sbt-app/src/sbt-test/plugins/plugin-cross/build.sbt
index bb7f00d89..3afc0f4c0 100644
--- a/sbt-app/src/sbt-test/plugins/plugin-cross/build.sbt
+++ b/sbt-app/src/sbt-test/plugins/plugin-cross/build.sbt
@@ -19,4 +19,4 @@ lazy val plugin = (projectMatrix in file("plugin"))
         case _      => "2.0.0-RC3"
     },
   )
-  .jvmPlatform(scalaVersions = Seq("3.8.3", "2.12.21"))
+  .jvmPlatform(scalaVersions = Seq("3.8.4", "2.12.21"))
diff --git a/sbt-app/src/sbt-test/plugins/sbt-native-packager/build.sbt b/sbt-app/src/sbt-test/plugins/sbt-native-packager/build.sbt
index efc5013d1..2b2ee3285 100644
--- a/sbt-app/src/sbt-test/plugins/sbt-native-packager/build.sbt
+++ b/sbt-app/src/sbt-test/plugins/sbt-native-packager/build.sbt
@@ -1,4 +1,4 @@
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 name := "hello"
 enablePlugins(JavaAppPackaging)
@@ -6,7 +6,7 @@ enablePlugins(JavaAppPackaging)
 lazy val check = taskKey[Unit]("")
 
 check := {
-  val cmd = "target/out/jvm/scala-3.8.3/hello/universal/stage/bin/hello"
+  val cmd = "target/out/jvm/scala-3.8.4/hello/universal/stage/bin/hello"
   val cmd0 =
     if (sys.props("os.name").toLowerCase(java.util.Locale.ROOT).contains("windows"))
       cmd + ".bat"
diff --git a/sbt-app/src/sbt-test/project-load/subdirectory/build.sbt b/sbt-app/src/sbt-test/project-load/subdirectory/build.sbt
index b6f6c3313..fa6c6b44f 100644
--- a/sbt-app/src/sbt-test/project-load/subdirectory/build.sbt
+++ b/sbt-app/src/sbt-test/project-load/subdirectory/build.sbt
@@ -3,7 +3,7 @@ lazy val foo = project
 @transient
 lazy val check = taskKey[Unit]("")
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 LocalRootProject / check := {
   assert((foo / Compile / scalacOptions).value == List("-Xmacro-settings:a:a"),
     s"${(foo / Compile / scalacOptions).value}")
diff --git a/sbt-app/src/sbt-test/project-load/werror/build.sbt b/sbt-app/src/sbt-test/project-load/werror/build.sbt
index 091230f32..144964006 100644
--- a/sbt-app/src/sbt-test/project-load/werror/build.sbt
+++ b/sbt-app/src/sbt-test/project-load/werror/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 @deprecated
 def foo = true
diff --git a/sbt-app/src/sbt-test/project-load/werror/changes/build.sbt b/sbt-app/src/sbt-test/project-load/werror/changes/build.sbt
index 443839160..0673d832b 100644
--- a/sbt-app/src/sbt-test/project-load/werror/changes/build.sbt
+++ b/sbt-app/src/sbt-test/project-load/werror/changes/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 @deprecated
 def foo = true
diff --git a/sbt-app/src/sbt-test/project-matrix/full/build.sbt b/sbt-app/src/sbt-test/project-matrix/full/build.sbt
index af62b21fe..a10f4c756 100644
--- a/sbt-app/src/sbt-test/project-matrix/full/build.sbt
+++ b/sbt-app/src/sbt-test/project-matrix/full/build.sbt
@@ -1,5 +1,5 @@
 lazy val scala3_LTS = "3.3.5"
-lazy val scala3_current = "3.8.3"
+lazy val scala3_current = "3.8.4"
 lazy val check = taskKey[Unit]("")
 
 organization := "com.example"
diff --git a/sbt-app/src/sbt-test/project-matrix/full/test b/sbt-app/src/sbt-test/project-matrix/full/test
index 6be1d54a0..c45b24c55 100644
--- a/sbt-app/src/sbt-test/project-matrix/full/test
+++ b/sbt-app/src/sbt-test/project-matrix/full/test
@@ -1,4 +1,4 @@
 > packageBin
 $ exists target/**/app_3.3.5-0.1.0-SNAPSHOT.jar
-$ exists target/**/app_3.8.3-0.1.0-SNAPSHOT.jar
-> core3_8_3/check
+$ exists target/**/app_3.8.4-0.1.0-SNAPSHOT.jar
+> core3_8_4/check
diff --git a/sbt-app/src/sbt-test/project-matrix/source-dep/build.sbt b/sbt-app/src/sbt-test/project-matrix/source-dep/build.sbt
index 554ccd414..f88ec331c 100644
--- a/sbt-app/src/sbt-test/project-matrix/source-dep/build.sbt
+++ b/sbt-app/src/sbt-test/project-matrix/source-dep/build.sbt
@@ -1,5 +1,5 @@
 // https://github.com/sbt/sbt/issues/8971
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 lazy val extLib = ProjectRef(file("ext/lib"), "lib")
 
diff --git a/sbt-app/src/sbt-test/project-matrix/source-dep/ext/lib/build.sbt b/sbt-app/src/sbt-test/project-matrix/source-dep/ext/lib/build.sbt
index 9ac698ff6..8466a855b 100644
--- a/sbt-app/src/sbt-test/project-matrix/source-dep/ext/lib/build.sbt
+++ b/sbt-app/src/sbt-test/project-matrix/source-dep/ext/lib/build.sbt
@@ -1,7 +1,7 @@
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 lazy val lib = (projectMatrix in file("."))
   .settings(
     name := "lib",
   )
-  .jvmPlatform(scalaVersions = Seq("3.8.3"))
+  .jvmPlatform(scalaVersions = Seq("3.8.4"))
diff --git a/sbt-app/src/sbt-test/project/Class.forName/build.sbt b/sbt-app/src/sbt-test/project/Class.forName/build.sbt
index 768c1f6c5..d660b858e 100644
--- a/sbt-app/src/sbt-test/project/Class.forName/build.sbt
+++ b/sbt-app/src/sbt-test/project/Class.forName/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 crossPaths := false
 name := "definition-lib-forname-test"
 version := "1.0"
diff --git a/sbt-app/src/sbt-test/project/nested-macro/build.sbt b/sbt-app/src/sbt-test/project/nested-macro/build.sbt
index 50df53547..e70a11d5e 100644
--- a/sbt-app/src/sbt-test/project/nested-macro/build.sbt
+++ b/sbt-app/src/sbt-test/project/nested-macro/build.sbt
@@ -1,6 +1,6 @@
 lazy val a1 = settingKey[Boolean]("")
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 a1 := true
 
 Compile / sourceGenerators += {
diff --git a/sbt-app/src/sbt-test/project/no-delegate/build.sbt b/sbt-app/src/sbt-test/project/no-delegate/build.sbt
index 26462895c..946aaf53f 100644
--- a/sbt-app/src/sbt-test/project/no-delegate/build.sbt
+++ b/sbt-app/src/sbt-test/project/no-delegate/build.sbt
@@ -1 +1 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
diff --git a/sbt-app/src/sbt-test/project/remove/build.sbt b/sbt-app/src/sbt-test/project/remove/build.sbt
index 80f0ae435..eab339c5a 100644
--- a/sbt-app/src/sbt-test/project/remove/build.sbt
+++ b/sbt-app/src/sbt-test/project/remove/build.sbt
@@ -11,7 +11,7 @@ lazy val intsSetting2 = Def.setting {
   Seq(1, 2, 3)
 }
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 intsTask := Seq(1, 2, 3, 4, 5, 6, 7)
 intsTask -= 3
@@ -30,10 +30,10 @@ intsSetting -= intSetting2.value
 intsSetting --= intsSetting2.value
 
 intsFromScalaV := Seq(1, 2, 3, 4, 5, 6, 7)
-intsFromScalaV -= { if scalaVersion.value == "3.8.3" then 3 else 5 }
-intsFromScalaV --= { if scalaVersion.value == "3.8.3" then Seq(1, 2) else Seq(4) }
-intsFromScalaV -= { if scalaVersion.value == "3.8.3" then Option(6) else None }
-intsFromScalaV --= { if scalaVersion.value == "3.8.3" then Option(7) else None }
+intsFromScalaV -= { if scalaVersion.value == "3.8.4" then 3 else 5 }
+intsFromScalaV --= { if scalaVersion.value == "3.8.4" then Seq(1, 2) else Seq(4) }
+intsFromScalaV -= { if scalaVersion.value == "3.8.4" then Option(6) else None }
+intsFromScalaV --= { if scalaVersion.value == "3.8.4" then Option(7) else None }
 
 intsSetSetting := Set(1, 2, 3, 4, 5, 6, 7)
 intsSetSetting -= 3
diff --git a/sbt-app/src/sbt-test/project/scala3-console-project/build.sbt b/sbt-app/src/sbt-test/project/scala3-console-project/build.sbt
index 4ce54ef9f..952762ced 100644
--- a/sbt-app/src/sbt-test/project/scala3-console-project/build.sbt
+++ b/sbt-app/src/sbt-test/project/scala3-console-project/build.sbt
@@ -1,4 +1,4 @@
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 lazy val markerFile = settingKey[java.io.File]("marker file written by consoleProject REPL when bindings resolve")
 
diff --git a/sbt-app/src/sbt-test/project/settings-delegate/build.sbt b/sbt-app/src/sbt-test/project/settings-delegate/build.sbt
index 26462895c..946aaf53f 100644
--- a/sbt-app/src/sbt-test/project/settings-delegate/build.sbt
+++ b/sbt-app/src/sbt-test/project/settings-delegate/build.sbt
@@ -1 +1 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
diff --git a/sbt-app/src/sbt-test/tests/fork-main-resources/build.sbt b/sbt-app/src/sbt-test/tests/fork-main-resources/build.sbt
index ee5a70376..ff75b0468 100644
--- a/sbt-app/src/sbt-test/tests/fork-main-resources/build.sbt
+++ b/sbt-app/src/sbt-test/tests/fork-main-resources/build.sbt
@@ -1,6 +1,6 @@
 val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 Test / fork := true
 libraryDependencies += scalatest % Test
 
diff --git a/sbt-app/src/sbt-test/tests/fork2/build.sbt b/sbt-app/src/sbt-test/tests/fork2/build.sbt
index 7a0fc6589..670c0be28 100644
--- a/sbt-app/src/sbt-test/tests/fork2/build.sbt
+++ b/sbt-app/src/sbt-test/tests/fork2/build.sbt
@@ -1,5 +1,5 @@
 val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
 
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 fork := true
 libraryDependencies += scalatest % Test
diff --git a/sbt-app/src/sbt-test/tests/incremental-object-deps/build.sbt b/sbt-app/src/sbt-test/tests/incremental-object-deps/build.sbt
index bc5c7b183..e18395371 100644
--- a/sbt-app/src/sbt-test/tests/incremental-object-deps/build.sbt
+++ b/sbt-app/src/sbt-test/tests/incremental-object-deps/build.sbt
@@ -1,3 +1,3 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 libraryDependencies += "com.eed3si9n.verify" %% "verify" % "1.0.0" % Test
 testFrameworks += new TestFramework("verify.runner.Framework")
diff --git a/sbt-app/src/sbt-test/tests/t543/build.sbt b/sbt-app/src/sbt-test/tests/t543/build.sbt
index 2a6120849..ff5147cd0 100644
--- a/sbt-app/src/sbt-test/tests/t543/build.sbt
+++ b/sbt-app/src/sbt-test/tests/t543/build.sbt
@@ -6,7 +6,7 @@ val marker = new File("marker")
 val check = TaskKey[Unit]("check", "Check correct error has been returned.")
 val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
 
-ThisBuild / scalaVersion := "3.8.3"
+ThisBuild / scalaVersion := "3.8.4"
 
 lazy val root = (project in file(".")).
   settings(
diff --git a/sbt-app/src/sbt-test/tests/test-option/build.sbt b/sbt-app/src/sbt-test/tests/test-option/build.sbt
index c23671f79..e0ad9f773 100644
--- a/sbt-app/src/sbt-test/tests/test-option/build.sbt
+++ b/sbt-app/src/sbt-test/tests/test-option/build.sbt
@@ -1,2 +1,2 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 libraryDependencies += "org.scalameta" %% "munit" % "0.7.29" % Test
diff --git a/server-test/src/server-test/channel-cursor/build.sbt b/server-test/src/server-test/channel-cursor/build.sbt
index 4d170479b..924f5b8e1 100644
--- a/server-test/src/server-test/channel-cursor/build.sbt
+++ b/server-test/src/server-test/channel-cursor/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 val printCurrentProject = inputKey[Unit]("Prints current project name")
 
diff --git a/server-test/src/server-test/client/build.sbt b/server-test/src/server-test/client/build.sbt
index b26c7209d..84fa4ac66 100644
--- a/server-test/src/server-test/client/build.sbt
+++ b/server-test/src/server-test/client/build.sbt
@@ -1,4 +1,4 @@
-scalaVersion := "3.8.3"
+scalaVersion := "3.8.4"
 
 TaskKey[Unit]("willSucceed") := println("success")