diff --git a/lib/flame/pool.ex b/lib/flame/pool.ex
index cc18ae6..d703ad8 100644
--- a/lib/flame/pool.ex
+++ b/lib/flame/pool.ex
@@ -544,7 +544,7 @@ defmodule FLAME.Pool do
 
       runner_count < state.max ->
         if state.async_boot_timer ||
-             map_size(state.pending_runners) * state.max_concurrency > Queue.size(state.waiting) do
+             map_size(state.pending_runners) * state.max_concurrency > waiting_count(state) do
           waiting_in(state, deadline, from)
         else
           state
@@ -797,7 +797,7 @@ defmodule FLAME.Pool do
   end
 
   defp has_unmet_servicable_demand?(%Pool{} = state) do
-    waiting_count(state) > 0 and runner_count(state) < state.max
+    waiting_count(state) > map_size(state.pending_runners) * state.max_concurrency and runner_count(state) < state.max
   end
 
   defp handle_runner_async_up(%Pool{} = state, pid, ref) when is_pid(pid) and is_reference(ref) do
@@ -813,27 +813,20 @@ defmodule FLAME.Pool do
     # 2. the case where we process a DOWN for the new runner as we pop DOWNs
     #   looking for fresh waiting
     # 3. if we still have waiting callers at the end, boot more runners if we have capacity
-    new_state =
-      Enum.reduce_while(1..state.max_concurrency, new_state, fn i, acc ->
-        with {:ok, %RunnerState{} = runner} <- Map.fetch(acc.runners, runner.monitor_ref),
-             true <- i <= acc.max_concurrency do
-          case pop_next_waiting_caller(acc) do
-            {%WaitingState{} = next, acc} ->
-              {:cont, reply_runner_checkout(acc, runner, next.from, next.monitor_ref)}
-
-            {nil, acc} ->
-              {:halt, acc}
-          end
-        else
-          _ -> {:halt, acc}
+    Enum.reduce_while(1..state.max_concurrency, new_state, fn i, acc ->
+      with {:ok, %RunnerState{} = runner} <- Map.fetch(acc.runners, runner.monitor_ref),
+            true <- i <= acc.max_concurrency do
+        case pop_next_waiting_caller(acc) do
+          {%WaitingState{} = next, acc} ->
+            {:cont, reply_runner_checkout(acc, runner, next.from, next.monitor_ref)}
+
+          {nil, acc} ->
+            {:halt, acc}
         end
-      end)
-
-    if has_unmet_servicable_demand?(new_state) do
-      async_boot_runner(new_state)
-    else
-      new_state
-    end
+      else
+        _ -> {:halt, acc}
+      end
+    end)
   end
 
   defp deadline(timeout) when is_integer(timeout) do