diff --git a/.tool-versions b/.tool-versions
index 003683012d..520cf2fc80 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-java temurin-17.0.12+7
-maven 3.8.4
+java temurin-21.0.1+12.0.LTS
+maven 3.9.9
diff --git a/README.md b/README.md
index 6006a33766..4351cf52f5 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ For more information on Connectors, refer to the
 ## Contents
 
 * [License](#license)
+* [Setup](#setup)
 * [Create a Connector](#create-a-connector)
     * [Outbound Connector](#outbound-connector)
     * [Inbound Connector](#inbound-connector)
@@ -41,6 +42,15 @@ This is a multi-module project with different licenses applied to different modu
 
 When in doubt, refer to the `LICENSE` file in the respective module.
 
+## Setup
+
+Download these utilities:
+
+* [`make`](https://www.gnu.org/software/make/) for building
+* [`asdf`](https://asdf-vm.com/) for managing Java and Maven versions
+
+The [Connector SDK](connector-sdk) uses Java 17, unlike the rest of this repository.
+
 ## Create a Connector
 
 Include the [connector-core](connector-sdk/core), e.g. via Maven: