diff --git a/scripts/wk/cfg/hw.py b/scripts/wk/cfg/hw.py
index d0d1efb1..1ef7513c 100644
--- a/scripts/wk/cfg/hw.py
+++ b/scripts/wk/cfg/hw.py
@@ -15,6 +15,7 @@ ATTRIBUTE_COLORS = (
   ('Maximum', 'PURPLE'),
   )
 # NOTE: Force 4K read block size for disks >= 3TB
+BADBLOCKS_EXTRA_LARGE_DISK = 15 * 1024**4
 BADBLOCKS_LARGE_DISK = 3 * 1024**4
 BADBLOCKS_REGEX = re.compile(
   r'^Pass completed, (\d+) bad blocks found. .(\d+)/(\d+)/(\d+) errors',
diff --git a/scripts/wk/hw/surface_scan.py b/scripts/wk/hw/surface_scan.py
index 50e7eecd..49afd25c 100644
--- a/scripts/wk/hw/surface_scan.py
+++ b/scripts/wk/hw/surface_scan.py
@@ -6,6 +6,7 @@ import logging
 from subprocess import STDOUT
 
 from wk.cfg.hw import (
+  BADBLOCKS_EXTRA_LARGE_DISK,
   BADBLOCKS_LARGE_DISK,
   BADBLOCKS_REGEX,
   BADBLOCKS_RESULTS_REGEX,
@@ -68,6 +69,8 @@ def run_scan(test_obj, log_path, test_mode=False) -> None:
   test_obj.set_status('Working')
 
   # Increase block size if necessary
+  if dev.size >= BADBLOCKS_EXTRA_LARGE_DISK:
+    block_size = '8192'
   if (dev.phy_sec == 4096
       or dev.size >= BADBLOCKS_LARGE_DISK):
     block_size = '4096'