diff --git a/java/config/config.go b/java/config/config.go
index 83c27d309..009813078 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -133,7 +133,12 @@ func init() {
 		if override := ctx.Config().Getenv("OVERRIDE_JLINK_VERSION_NUMBER"); override != "" {
 			return override
 		}
-		return "17"
+		switch ctx.Config().Getenv("EXPERIMENTAL_USE_OPENJDK21_TOOLCHAIN") {
+		case "true":
+			return "21"
+		default:
+			return "17"
+		}
 	})
 
 	pctx.SourcePathVariable("JavaToolchain", "${JavaHome}/bin")
diff --git a/ui/build/config.go b/ui/build/config.go
index d345415b5..613fc6537 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -384,10 +384,14 @@ func NewConfig(ctx Context, args ...string) Config {
 	// Configure Java-related variables, including adding it to $PATH
 	java8Home := filepath.Join("prebuilts/jdk/jdk8", ret.HostPrebuiltTag())
 	java17Home := filepath.Join("prebuilts/jdk/jdk17", ret.HostPrebuiltTag())
+	java21Home := filepath.Join("prebuilts/jdk/jdk21", ret.HostPrebuiltTag())
 	javaHome := func() string {
 		if override, ok := ret.environ.Get("OVERRIDE_ANDROID_JAVA_HOME"); ok {
 			return override
 		}
+		if ret.environ.IsEnvTrue("EXPERIMENTAL_USE_OPENJDK21_TOOLCHAIN") {
+			return java21Home
+		}
 		if toolchain11, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN"); ok && toolchain11 != "true" {
 			ctx.Fatalln("The environment variable EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN is no longer supported. An OpenJDK 11 toolchain is now the global default.")
 		}