diff --git a/lib/broadway/process.ex b/lib/broadway/process.ex
index 1539ff4..a12340e 100644
--- a/lib/broadway/process.ex
+++ b/lib/broadway/process.ex
@@ -9,12 +9,16 @@ defmodule Broadway.Process do
       Process.set_label(label)
     end
 
-    def labels_supported?, do: true
+    # We don't use just "true" because callers would likely get type warnings,
+    # so we trick the compiler into this being dynamic.
+    def labels_supported?, do: :rand.uniform() >= 0.0
   else
     def set_label(_label) do
       :ok
     end
 
-    def labels_supported?, do: false
+    # We don't use just "true" because callers would likely get type warnings,
+    # so we trick the compiler into this being dynamic.
+    def labels_supported?, do: :rand.uniform() > 1.1
   end
 end
diff --git a/lib/broadway/topology/producer_stage.ex b/lib/broadway/topology/producer_stage.ex
index 1d2395b..87c3a56 100644
--- a/lib/broadway/topology/producer_stage.ex
+++ b/lib/broadway/topology/producer_stage.ex
@@ -292,7 +292,7 @@ defmodule Broadway.Topology.ProducerStage do
 
   defp maybe_rate_limit_and_buffer_messages(state, messages) do
     if state.rate_limiting && messages != [] do
-      state = update_in(state.rate_limiting.message_buffer, &enqueue_batch(&1, messages))
+      state = update_in(state.rate_limiting.message_buffer, &:queue.in(messages, &1))
       rate_limit_and_buffer_messages(state)
     else
       {state, messages}
@@ -372,9 +372,6 @@ defmodule Broadway.Topology.ProducerStage do
     end
   end
 
-  defp enqueue_batch(queue, _list = []), do: queue
-  defp enqueue_batch(queue, list), do: :queue.in(list, queue)
-
   defp enqueue_batch_r(queue, _list = []), do: queue
   defp enqueue_batch_r(queue, list), do: :queue.in_r(list, queue)
 
diff --git a/mix.exs b/mix.exs
index 6bb85ed..59b7cad 100644
--- a/mix.exs
+++ b/mix.exs
@@ -14,8 +14,7 @@ defmodule Broadway.MixProject do
       deps: deps(),
       docs: docs(),
       package: package(),
-      test_coverage: [tool: ExCoveralls],
-      preferred_cli_env: [docs: :docs]
+      test_coverage: [tool: ExCoveralls]
     ]
   end
 
@@ -40,6 +39,10 @@ defmodule Broadway.MixProject do
     ]
   end
 
+  def cli do
+    [preferred_envs: [docs: :docs]]
+  end
+
   defp docs do
     [
       main: "introduction",
diff --git a/test/test_helper.exs b/test/test_helper.exs
index 65f26dd..fb40ccc 100644
--- a/test/test_helper.exs
+++ b/test/test_helper.exs
@@ -1,2 +1 @@
 ExUnit.start(capture_log: true, assert_receive_timeout: 2000)
-Logger.remove_backend(:console)