diff --git a/pkg/private/deb/make_deb.py b/pkg/private/deb/make_deb.py
index 8fae6b7b..ce832c31 100644
--- a/pkg/private/deb/make_deb.py
+++ b/pkg/private/deb/make_deb.py
@@ -101,7 +101,12 @@ def AddArFileEntry(fileobj, filename,
   if isinstance(content, (str, bytes)):
     content_len, content = ConvertToFileLike(content, content_len, io.BytesIO)
   inputs = [
-      (filename + '/').ljust(16),  # filename (SysV)
+      # SysV/GNU ar convention is <name>/<space padding>.
+      # That breaks BSD version of ar, which does not support spaces in names.
+      # macos is BSD style, most linux are GNU style.
+      # dbpk-deb writes without a slash
+      # dpkg is happy to read either way since about 1.15.6
+      filename.ljust(16),  # filename (no '/' terminator, matches dpkg-deb)
       str(timestamp).ljust(12),  # timestamp
       str(owner_id).ljust(6),  # owner id
       str(group_id).ljust(6),  # group id
diff --git a/tests/deb/pkg_deb_test.py b/tests/deb/pkg_deb_test.py
index 120ada1a..81b65690 100644
--- a/tests/deb/pkg_deb_test.py
+++ b/tests/deb/pkg_deb_test.py
@@ -133,6 +133,28 @@ def assert_tar_stream_content(self, data, expected, match_order=True):
       if i < len(expected):
         self.fail('Missing file %s' % expected[i])
 
+  def test_ar_member_names(self):
+    # Read the raw ar headers rather than using SimpleArReader, which
+    # tolerates the SysV '/' name terminator. dpkg-deb writes plain names
+    # padded with spaces, so we should too.
+    names = []
+    with open(self.deb_path, 'rb') as f:
+      self.assertEqual(f.read(8), b'!<arch>\n')
+      while True:
+        header = f.read(60)
+        if not header:
+          break
+        self.assertEqual(len(header), 60)
+        self.assertEqual(header[58:60], b'\x60\x0a')
+        names.append(header[0:16])
+        size = int(header[48:58].strip())
+        f.seek(size + (size % 2), os.SEEK_CUR)
+    self.assertEqual(names, [
+        b'debian-binary   ',
+        b'control.tar.gz  ',
+        b'data.tar.gz     ',
+    ])
+
   def test_expected_files(self):
     # Check the set of 'test-tar-basic-*' smoke test.
     expected = [