diff --git a/README.md b/README.md
index 1e8fe2a..c792b48 100644
--- a/README.md
+++ b/README.md
@@ -101,7 +101,7 @@ If you already have a PyPI repo, use `genlocal` first to generate a local db:
 `verify` command accepts same arguments as sync, and accepts some new arguments. Please check `./shadowmire.py verify --help` for more information.
 
 > [!TIP]
-> You could set `SHADOWMIRE_IOWORKERS` environment variable to a number to set threads to do local I/O. Defaults to 5.
+> You could set `SHADOWMIRE_IOWORKERS` environment variable to a number to set threads to do local I/O. Defaults to 2.
 
 > [!IMPORTANT]
 > For users switching from Bandersnatch to Shadowmire, you **MUST** run the following commands (with exclusion, of course) before regular syncing:
diff --git a/shadowmire.py b/shadowmire.py
index 45db6ae..fd186c2 100755
--- a/shadowmire.py
+++ b/shadowmire.py
@@ -37,7 +37,7 @@ USER_AGENT = "Shadowmire (https://github.com/taoky/shadowmire)"
 # Note that it's suggested to use only 3 workers for PyPI.
 WORKERS = int(os.environ.get("SHADOWMIRE_WORKERS", "3"))
 # Use threads to parallelize verification local IO
-IOWORKERS = int(os.environ.get("SHADOWMIRE_IOWORKERS", "5"))
+IOWORKERS = int(os.environ.get("SHADOWMIRE_IOWORKERS", "2"))
 # A safety net -- to avoid upstream issues casuing too many packages removed when determinating sync plan.
 MAX_DELETION = int(os.environ.get("SHADOWMIRE_MAX_DELETION", "50000"))