diff --git a/lib/jgit/BUCK b/lib/jgit/BUCK
index 9f8a5c9d82..3e481bfd3e 100644
--- a/lib/jgit/BUCK
+++ b/lib/jgit/BUCK
@@ -10,6 +10,7 @@ maven_jar(
   src_sha1 = 'b4e3d9c9c3da39b72acf72bd913ce9dbee88a9d4',
   license = 'jgit',
   repository = REPO,
+  unsign = True,
   deps = [':ewah'],
   exclude = [
     'META-INF/eclipse.inf',
diff --git a/lib/maven.defs b/lib/maven.defs
index d49fed6e12..54840e89ac 100644
--- a/lib/maven.defs
+++ b/lib/maven.defs
@@ -33,6 +33,7 @@ def maven_jar(
     license,
     exclude = [],
     exclude_java_sources = False,
+    unsign = False,
     deps = [],
     sha1 = '', bin_sha1 = '', src_sha1 = '',
     repository = MAVEN_CENTRAL,
@@ -73,6 +74,8 @@ def maven_jar(
     cmd.extend(['-x', x])
   if exclude_java_sources:
     cmd.append('--exclude_java_sources')
+  if unsign:
+    cmd.append('--unsign')
 
   genrule(
     name = name + '__download_bin',
diff --git a/tools/download_file.py b/tools/download_file.py
index 2fcce3fbac..8d76a40ea9 100755
--- a/tools/download_file.py
+++ b/tools/download_file.py
@@ -109,6 +109,7 @@ opts.add_option('-u', help='URL to download')
 opts.add_option('-v', help='expected content SHA-1')
 opts.add_option('-x', action='append', help='file to delete from ZIP')
 opts.add_option('--exclude_java_sources', action='store_true')
+opts.add_option('--unsign', action='store_true')
 args, _ = opts.parse_args()
 
 root_dir = args.o
@@ -166,7 +167,22 @@ if args.exclude_java_sources:
     finally:
       zf.close()
   except (BadZipfile, LargeZipFile) as err:
-    print("error opening %s: %s"  % (cache_ent, err), file=stderr)
+    print('error opening %s: %s'  % (cache_ent, err), file=stderr)
+    exit(1)
+
+if args.unsign:
+  try:
+    zf = ZipFile(cache_ent, 'r')
+    try:
+      for n in zf.namelist():
+        if (n.endswith('.RSA')
+            or n.endswith('.SF')
+            or n.endswith('.LIST')):
+          exclude.append(n)
+    finally:
+      zf.close()
+  except (BadZipfile, LargeZipFile) as err:
+    print('error opening %s: %s'  % (cache_ent, err), file=stderr)
     exit(1)
 
 safe_mkdirs(path.dirname(args.o))
@@ -174,7 +190,7 @@ if exclude:
   try:
     shutil.copyfile(cache_ent, args.o)
   except (shutil.Error, IOError) as err:
-    print("error copying to %s: %s" % (args.o, err), file=stderr)
+    print('error copying to %s: %s' % (args.o, err), file=stderr)
     exit(1)
   try:
     check_call(['zip', '-d', args.o] + exclude)
@@ -188,5 +204,5 @@ else:
     try:
       shutil.copyfile(cache_ent, args.o)
     except (shutil.Error, IOError) as err:
-      print("error copying to %s: %s" % (args.o, err), file=stderr)
+      print('error copying to %s: %s' % (args.o, err), file=stderr)
       exit(1)