diff --git a/.java-version b/.java-version
deleted file mode 100644
index 3a560a7e..00000000
--- a/.java-version
+++ /dev/null
@@ -1 +0,0 @@
-11.0.20
diff --git a/.tool-versions b/.tool-versions
index 58dcdfd2..0ef52de3 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1 +1 @@
-java corretto-11.0.25.9.1
+java corretto-21
diff --git a/README.md b/README.md
index c93f44b9..22107d80 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ Running locally
 ------------------------------
 1. Get Deploy Tools Janus credentials.
 2. Run `./scripts/setup`
-3. Ensure you are running Java 11
+3. Ensure you are running Java 21
 4. Run `sbt`
 5. Start the application: `sbt:prism> run`
 
diff --git a/app/agent/origin.scala b/app/agent/origin.scala
index d6bea311..7c169e72 100644
--- a/app/agent/origin.scala
+++ b/app/agent/origin.scala
@@ -1,7 +1,7 @@
 package agent
 
 import java.io.FileNotFoundException
-import java.net.{URI, URL, URLConnection, URLStreamHandler}
+import java.net.URI
 
 import collectors.Instance
 import conf.{AWS, PrismConfiguration}
@@ -206,17 +206,6 @@ case class JsonOrigin(
     crawlRate: Map[String, CrawlRate]
 ) extends Origin
     with Logging {
-  private val classpathHandler = new URLStreamHandler {
-    override def openConnection(u: URL): URLConnection = {
-      Option(getClass.getResource(u.getPath))
-        .map(_.openConnection())
-        .getOrElse {
-          throw new FileNotFoundException(
-            "%s not found on classpath" format u.getPath
-          )
-        }
-    }
-  }
 
   def credsFromS3Url(url: URI): AwsCredentialsProvider = {
     Option(url.getUserInfo) match {
@@ -237,10 +226,11 @@ case class JsonOrigin(
       url.replace("%resource%", resource.name)
     ) match {
       case classPathLocation if classPathLocation.getScheme == "classpath" =>
-        Source.fromURL(
-          new URL(null, classPathLocation.toString, classpathHandler),
-          "utf-8"
-        )
+        val path = classPathLocation.getPath
+        val resourceURL = Option(getClass.getResource(path)).getOrElse {
+          throw new FileNotFoundException(s"$path not found on classpath")
+        }
+        Source.fromURL(resourceURL, "utf-8")
       case s3Location if s3Location.getScheme == "s3" =>
         val s3Client = S3Client.builder
           .credentialsProvider(credsFromS3Url(s3Location))
diff --git a/cdk/lib/prism.ts b/cdk/lib/prism.ts
index f18d3dc8..49ee1da1 100644
--- a/cdk/lib/prism.ts
+++ b/cdk/lib/prism.ts
@@ -89,7 +89,7 @@ export class Prism extends GuStack {
 			applicationLogging: {
 				enabled: true,
 			},
-			imageRecipe: 'arm64-focal-java11-deploy-infrastructure',
+			imageRecipe: 'arm64-jammy-java21-deploy-infrastructure',
 			instanceType: InstanceType.of(InstanceClass.T4G, InstanceSize.MEDIUM),
 			userData,
 			certificateProps: {