diff --git a/lib/pipeline/rpc/router.rb b/lib/pipeline/rpc/router.rb
index dfb2695..51b0dea 100644
--- a/lib/pipeline/rpc/router.rb
+++ b/lib/pipeline/rpc/router.rb
@@ -92,6 +92,7 @@ module Pipeline::Rpc
       elsif msg.type == "worker_heartbeat"
         identity = msg.parsed_msg["identity"]
         queues = msg.parsed_msg["workqueue_addresses"]
+        puts "worker heartbeat #{msg.parsed_msg}"
         @worker_presence.mark_seen!(identity, queues)
       else
         puts "Unrecognised message: #{msg.type} #{msg.parsed_msg}"
diff --git a/lib/pipeline/runtime/runtime_environment.rb b/lib/pipeline/runtime/runtime_environment.rb
index 665b231..6b132a3 100644
--- a/lib/pipeline/runtime/runtime_environment.rb
+++ b/lib/pipeline/runtime/runtime_environment.rb
@@ -51,11 +51,10 @@ module Pipeline::Runtime
       release_container(language_slug, version, container_repo)
     end
 
-    def list_deployed_containers(track_slug)
-      track_dir = "#{env_base}/#{track_slug}"
-      glob_pattern = "#{track_dir}/*/current"
+    def list_deployed_containers
+      glob_pattern = "#{env_base}/*/*/current"
       Dir.glob(glob_pattern).map do |match|
-        match.gsub(track_dir, "").gsub(/current$/, "")
+        match.gsub(env_base, "").gsub(/current$/, "")
       end
     end