diff --git a/apps/indexer/lib/indexer/block/catchup/fetcher.ex b/apps/indexer/lib/indexer/block/catchup/fetcher.ex
index 93dfeca104e3..a4cdbbfb5f47 100644
--- a/apps/indexer/lib/indexer/block/catchup/fetcher.ex
+++ b/apps/indexer/lib/indexer/block/catchup/fetcher.ex
@@ -34,7 +34,7 @@ defmodule Indexer.Block.Catchup.Fetcher do
   # DO NOT use them directly in the code.  Get options from `state`.
 
   @blocks_batch_size 10
-  @blocks_concurrency 10
+  @blocks_concurrency 5
   @sequence_name :block_catchup_sequencer
 
   defstruct blocks_batch_size: @blocks_batch_size,