diff --git a/java-compiler-testing/src/main/java/io/github/ascopes/jct/containers/impl/PackageContainerGroupUrlClassLoader.java b/java-compiler-testing/src/main/java/io/github/ascopes/jct/containers/impl/PackageContainerGroupUrlClassLoader.java
index c2dd562a0..9776d048b 100644
--- a/java-compiler-testing/src/main/java/io/github/ascopes/jct/containers/impl/PackageContainerGroupUrlClassLoader.java
+++ b/java-compiler-testing/src/main/java/io/github/ascopes/jct/containers/impl/PackageContainerGroupUrlClassLoader.java
@@ -15,7 +15,9 @@
  */
 package io.github.ascopes.jct.containers.impl;
 
+import io.github.ascopes.jct.containers.Container;
 import io.github.ascopes.jct.containers.PackageContainerGroup;
+import io.github.ascopes.jct.workspaces.PathRoot;
 import java.net.URL;
 import java.net.URLClassLoader;
 import javax.annotation.concurrent.ThreadSafe;
@@ -46,14 +48,10 @@ public PackageContainerGroupUrlClassLoader(PackageContainerGroup group) {
   }
 
   private static URL[] extractUrls(PackageContainerGroup group) {
-    // TODO(ascopes): should this API return a list to simplify this?
-    var pkgs = group.getPackages();
-    var iter = pkgs.iterator();
-    var urls = new URL[pkgs.size()];
-
-    for (var i = 0; i < urls.length; ++i) {
-      urls[i] = iter.next().getPathRoot().getUrl();
-    }
-    return urls;
+    return group.getPackages()
+        .stream()
+        .map(Container::getPathRoot)
+        .map(PathRoot::getUrl)
+        .toArray(URL[]::new);
   }
 }