diff --git a/modules/logstash/files/elasticsearch.yml b/modules/logstash/files/elasticsearch.yml
index edd172109a..8bc5d1a120 100644
--- a/modules/logstash/files/elasticsearch.yml
+++ b/modules/logstash/files/elasticsearch.yml
@@ -139,6 +139,7 @@
 index.store.compress.stored: true
 index.store.compress.tv: true
 
+indices.memory.index_buffer_size: "40%"
 
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