diff --git a/build/signtools/signtool_v3.py b/build/signtools/signtool_v3.py
index 39bec9ecae53f536c26c33e9e3f84b303528bf2d..3d80e6a775622a69f1831cd86a190bd5156dce82 100755
--- a/build/signtools/signtool_v3.py
+++ b/build/signtools/signtool_v3.py
@@ -17,7 +17,6 @@
 import struct
 import os
 import stat
-import binascii
 import shutil
 import argparse
 import configparser
@@ -27,7 +26,6 @@ import logging
 
 from manifest import process_manifest_file
 from generate_signature import gen_ta_signature
-from Crypto.Hash import SHA256
 from Crypto.Cipher import PKCS1_OAEP
 from Crypto.PublicKey import RSA
 from Crypto.Cipher import AES