diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3a8284eb4..651696b5c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu"]
-        jvm: ["8", "11", "17", "20"]
+        jvm: ["8", "11", "17", "21"]
         include:
           - os: windows
             jvm: 17
diff --git a/docs/users/installation.md b/docs/users/installation.md
index 6329bb301..6b6f55ef3 100644
--- a/docs/users/installation.md
+++ b/docs/users/installation.md
@@ -3,17 +3,13 @@ id: installation
 title: Installation
 ---
 
-## Requirements
+## Support
 
-**macOS, Linux or Windows**: Scalafix runs on macOS, Linux and Windows. Every
-pull request is tested on both Linux and Windows.
+**macOS, Linux or Windows**
 
-**Java 8 or Java 11.**
+**Java LTS (8, 11, 17 or 21)**
 
-**Scala 2.12 and 2.13**
-
-**Scala 3.x**: Scala 3 support is experimental and many built-in rules are not
-supported.
+**Scala 2.12, 2.13 or 3.x** (all rules are not available for Scala 3.x)
 
 ## sbt
 
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 395902318..778d25490 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -12,11 +12,19 @@ object Dependencies {
   val scala3 = sys.props.getOrElse("scala3.nightly", "3.3.1")
 
   val buildScalaVersions = Seq(scala212, scala213, scala3)
-  val buildWithTargetVersions: Seq[(String, String)] =
-    buildScalaVersions.map(sv => (sv, sv)) ++
+  val buildWithTargetVersions: Seq[(String, String)] = {
+    val all = buildScalaVersions.map(sv => (sv, sv)) ++
       Seq(scala213, scala212).flatMap(sv => previousVersions(sv).map(prev => (sv, prev))) ++
       Seq(scala213, scala212).map(sv => (sv, scala3))
 
+    all.filter {
+      case (_, v) if System.getProperty("java.version") == "21" =>
+        !Seq("2.12.16", "2.12.17", "2.13.10").contains(v)
+      case _ =>
+        true
+    }
+  }
+
   val bijectionCoreV = "0.9.7"
   val collectionCompatV = "2.11.0"
   val coursierV = "2.1.7"
@@ -28,7 +36,7 @@ object Dependencies {
   val metaconfigV = "0.12.0"
   val nailgunV = "0.9.1"
   val scalaXmlV = "2.2.0"
-  val scalametaV = "4.8.12"
+  val scalametaV = "4.8.13"
   val scalatestV = "3.2.17"
   val munitV = "0.7.29"