diff --git a/tools/releasetools/check_target_files_signatures b/tools/releasetools/check_target_files_signatures
index 17aebdc..2c97e2e 100755
--- a/tools/releasetools/check_target_files_signatures
+++ b/tools/releasetools/check_target_files_signatures
@@ -47,7 +47,6 @@
 
 import os
 import re
-import sha
 import shutil
 import subprocess
 import tempfile
@@ -112,7 +111,7 @@
         self.certs[cert] = self.certs[cert] + "," + name
     else:
       if name is None:
-        name = "unknown cert %s (%s)" % (sha.sha(cert).hexdigest()[:12],
+        name = "unknown cert %s (%s)" % (common.sha1(cert).hexdigest()[:12],
                                          GetCertSubject(cert))
       self.certs[cert] = name
 
@@ -245,7 +244,7 @@
     self.max_fn_len = 20
 
   def LoadZipFile(self, filename):
-    d = common.UnzipTemp(filename, '*.apk')
+    d, z = common.UnzipTemp(filename, '*.apk')
     try:
       self.apks = {}
       self.apks_by_basename = {}
@@ -263,7 +262,6 @@
     finally:
       shutil.rmtree(d)
 
-    z = zipfile.ZipFile(open(filename, "rb"))
     self.certmap = common.ReadApkCerts(z)
     z.close()