diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000..7e902b8c95
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "inox"]
+	path = inox
+	url = https://github.com/epfl-lara/inox.git
+	branch = main
diff --git a/README.md b/README.md
index e76b73ad3f..995b0eca27 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,11 @@ Hosted at https://github.com/epfl-lara/stainless ; mirrored at https://gitlab.ep
 
 Verification framework for a subset of the [Scala](http://scala-lang.org) programming language. See the [tutorial](https://epfl-lara.github.io/asplos2022tutorial/).
 
+Please note that this repository uses `git submodules`, so you need to either:
+
+- clone it with the `--recursive` option, or
+- run `$ git submodule update --init --recursive` after cloning.
+
 Please note that Stainless does not support Scala 2 frontend anymore but only Scala 3.3. The latest release that does support Scala 2.13 frontend is the [v0.9.8.7](https://github.com/epfl-lara/stainless/releases/tag/v0.9.8.7).
 
 ## Quick start
diff --git a/build.sbt b/build.sbt
index 3bdd0e1a18..1a2c2d81c9 100644
--- a/build.sbt
+++ b/build.sbt
@@ -275,8 +275,7 @@ val scriptSettings: Seq[Setting[_]] = Seq(
 
 def ghProject(repo: String, version: String) = RootProject(uri(s"${repo}#${version}"))
 
-// lazy val inox = RootProject(file("../inox"))
-lazy val inox = ghProject("https://github.com/epfl-lara/inox.git", "3b02dcf4308f9e8d74ea82304bd651be8e93517f")
+lazy val inox = RootProject(file("./inox"))
 lazy val cafebabe = ghProject("https://github.com/epfl-lara/cafebabe.git", "616e639b34379e12b8ac202849de3ebbbd0848bc")
 
 // Allow integration test to use facilities from regular tests
diff --git a/inox b/inox
new file mode 160000
index 0000000000..9fdb4d4941
--- /dev/null
+++ b/inox
@@ -0,0 +1 @@
+Subproject commit 9fdb4d494133595fd832584e8aaa64b3f027fbab
diff --git a/sbt-plugin/src/main/scala/ch/epfl/lara/sbt/stainless/StainlessPlugin.scala b/sbt-plugin/src/main/scala/ch/epfl/lara/sbt/stainless/StainlessPlugin.scala
index 7ed8d3bf61..2711c45913 100644
--- a/sbt-plugin/src/main/scala/ch/epfl/lara/sbt/stainless/StainlessPlugin.scala
+++ b/sbt-plugin/src/main/scala/ch/epfl/lara/sbt/stainless/StainlessPlugin.scala
@@ -6,8 +6,10 @@ import java.nio.file.StandardCopyOption
 import java.util.stream.Collectors
 import java.util.zip.ZipFile
 import java.util.zip.ZipEntry
-import sbt._
-import sbt.Keys._
+import sbt.{Def, *}
+import sbt.Keys.*
+
+import java.io
 
 object StainlessPlugin extends sbt.AutoPlugin {
   private val IssueTracker = "https://github.com/epfl-lara/stainless/issues"
@@ -26,7 +28,7 @@ object StainlessPlugin extends sbt.AutoPlugin {
     val stainlessExtraResolvers = settingKey[Seq[sbt.librarymanagement.MavenRepository]]("Extra resolvers to pass along to Stainless")
   }
 
-  import autoImport._
+  import autoImport.*
 
   /**
     * An (Ivy) configuration allowing us to manage dependencies outside of the project's classpath.
@@ -34,9 +36,9 @@ object StainlessPlugin extends sbt.AutoPlugin {
     */
   private val StainlessLibSources = config("stainless-lib").hide
 
-  override def globalSettings = Seq(
+  override def globalSettings: Seq[Def.Setting[?]] = Seq(
     onLoad := onLoad.value andThen checkProjectsScalaVersion,
-    stainlessExtraResolvers := Seq(Resolver.sonatypeRepo("releases"))
+    stainlessExtraResolvers  ++= Resolver.sonatypeOssRepos("snapshots")
   )
 
   /**
@@ -59,9 +61,9 @@ object StainlessPlugin extends sbt.AutoPlugin {
     state
   }
 
-  override lazy val projectSettings: Seq[Def.Setting[_]] = stainlessSettings
+  override lazy val projectSettings: Seq[Def.Setting[?]] = stainlessSettings
 
-  lazy val stainlessSettings: Seq[sbt.Def.Setting[_]] = Seq(
+  lazy val stainlessSettings: Seq[sbt.Def.Setting[?]] = Seq(
     stainlessVersion        := BuildInfo.stainlessVersion,
     stainlessEnabled        := true,
     stainlessExtraDeps      := Seq.empty,
@@ -98,7 +100,7 @@ object StainlessPlugin extends sbt.AutoPlugin {
     compilerPlugin(pluginRef) +: sourceDeps
   }
 
-  lazy val stainlessConfigSettings: Seq[Def.Setting[_]] =
+  lazy val stainlessConfigSettings: Seq[Def.Setting[?]] =
     Seq(
       managedSources ++= fetchAndUnzipSourceDeps.value,
       managedSourceDirectories += stainlessSourcesLocation.value
@@ -178,11 +180,11 @@ object StainlessPlugin extends sbt.AutoPlugin {
     var archive: ZipFile = null
     try {
       archive = new ZipFile(jar)
-      import scala.collection.JavaConverters._
+      import scala.collection.JavaConverters.*
       val entries: List[ZipEntry] = archive.stream().collect(Collectors.toList()).asScala.toList
       entries foreach { entry =>
-        val entryDest = destPath.resolve(entry.getName())
-        if (!entry.isDirectory()) {
+        val entryDest = destPath.resolve(entry.getName)
+        if (!entry.isDirectory) {
           Files.createDirectories(entryDest.getParent)
           Files.copy(archive.getInputStream(entry), entryDest, StandardCopyOption.REPLACE_EXISTING)
         }