diff --git a/lib/vessel/engine.rb b/lib/vessel/engine.rb
index 71505e0..cd37fe7 100644
--- a/lib/vessel/engine.rb
+++ b/lib/vessel/engine.rb
@@ -93,7 +93,7 @@ def idle?
     end
 
     def schedule(*requests)
-      requests.size.times { increase(:req_enqueued) }
+      requests.flatten.size.times { increase(:req_enqueued) }
       scheduler.post(*requests)
     end