diff --git a/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java b/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java
index b8dddc20cc51d..b1cb2023f7271 100644
--- a/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java
+++ b/server/src/main/java/org/elasticsearch/threadpool/DefaultBuiltInExecutorBuilders.java
@@ -43,7 +43,7 @@ public Map<String, ExecutorBuilder> getBuilders(Settings settings, int allocated
             new FixedExecutorBuilder(
                 settings,
                 ThreadPool.Names.WRITE,
-                allocatedProcessors,
+                halfProc > 1 ? halfProc : allocatedProcessors,
                 10000,
                 new EsExecutors.TaskTrackingConfig(true, indexAutoscalingEWMA)
             )