diff --git a/docs/reference/index-modules/merge.asciidoc b/docs/reference/index-modules/merge.asciidoc
index 81316fac535..abd20fb347a 100644
--- a/docs/reference/index-modules/merge.asciidoc
+++ b/docs/reference/index-modules/merge.asciidoc
@@ -201,18 +201,6 @@ spinning platter drives instead, decrease this to 1.
 [float]
 ==== SerialMergeScheduler
 
-A merge scheduler that simply does each merge sequentially using the
-calling thread (blocking the operations that triggered the merge or the
-index operation). This merge scheduler has a merge thread pool that
-explicitly schedules merges, and it makes sure that merges are serial
-within a shard, yet concurrent across multiple shards.
-
-The scheduler supports the following settings:
-
-`index.merge.scheduler.max_merge_at_once`::
-
-The maximum number of merges a single merge run performs. This setting prevents
-executing unlimited amount of merges in a loop until another shards has a
-chance to get a merge thread from the pool. If this limit is reached the
-merge thread returns to the pool and continues once the the call to a single
-shards is executed. The default is `5`
+This is accepted for backwards compatibility, but just uses
+ConcurrentMergeScheduler with index.merge.scheduler.max_thread_count
+set to 1 so that only 1 merge may run at a time.