diff --git a/tools/releasetools/check_target_files_signatures b/tools/releasetools/check_target_files_signatures
index 2c97e2e57..1325ef477 100755
--- a/tools/releasetools/check_target_files_signatures
+++ b/tools/releasetools/check_target_files_signatures
@@ -52,6 +52,11 @@ import subprocess
 import tempfile
 import zipfile
 
+try:
+  from hashlib import sha1 as sha1
+except ImportError:
+  from sha import sha as sha1
+
 import common
 
 # Work around a bug in python's zipfile module that prevents opening
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 40da73ac3..2cb5680ed 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -29,11 +29,9 @@ import time
 import zipfile
 
 try:
-  import hashlib
-  sha1 = hashlib.sha1
+  from hashlib import sha1 as sha1
 except ImportError:
-  import sha
-  sha1 = sha.sha
+  from sha import sha as sha1
 
 # missing in Python 2.4 and before
 if not hasattr(os, "SEEK_SET"):
diff --git a/tools/releasetools/ota_from_target_files b/tools/releasetools/ota_from_target_files
index 8f5c3fe86..aead38f4e 100755
--- a/tools/releasetools/ota_from_target_files
+++ b/tools/releasetools/ota_from_target_files
@@ -63,6 +63,11 @@ import tempfile
 import time
 import zipfile
 
+try:
+  from hashlib import sha1 as sha1
+except ImportError:
+  from sha import sha as sha1
+
 import common
 import edify_generator