diff --git a/Lib/msilib/__init__.py b/Lib/msilib/__init__.py
index f0370c2a0fe764..0dd6343bf58c4f 100644
--- a/Lib/msilib/__init__.py
+++ b/Lib/msilib/__init__.py
@@ -275,7 +275,7 @@ def start_component(self, component = None, feature = None, flags = None, keyfil
         if Win64:
             flags |= 256
         if keyfile:
-            keyid = self.cab.gen_id(self.absolute, keyfile)
+            keyid = self.cab.gen_id(keyfile)
             self.keyfiles[keyfile] = keyid
         else:
             keyid = None
diff --git a/Lib/test/test_msilib.py b/Lib/test/test_msilib.py
index fec435e05b747c..1de58b403f7a31 100644
--- a/Lib/test/test_msilib.py
+++ b/Lib/test/test_msilib.py
@@ -59,6 +59,15 @@ def test_get_property_vt_empty(self):
         del db
         self.addCleanup(unlink, db_path)
 
+    def test_directory_start_component_keyfile(self):
+        db, db_path = init_database()
+        self.addCleanup(db.Close)
+        feature = msilib.Feature(db, 0, 'Feature', 'A feature', 'Python')
+        cab = msilib.CAB('CAB')
+        dir = msilib.Directory(db, cab, None, TESTFN, 'TARGETDIR',
+                               'SourceDir', 0)
+        dir.start_component(None, feature, None, 'keyfile')
+
 
 class Test_make_id(unittest.TestCase):
     #http://msdn.microsoft.com/en-us/library/aa369212(v=vs.85).aspx
diff --git a/Misc/NEWS.d/next/Library/2019-05-30-16-16-47.bpo-12639.TQFOR4.rst b/Misc/NEWS.d/next/Library/2019-05-30-16-16-47.bpo-12639.TQFOR4.rst
new file mode 100644
index 00000000000000..aade9121b4bbbd
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-05-30-16-16-47.bpo-12639.TQFOR4.rst
@@ -0,0 +1,2 @@
+:meth:`msilib.Directory.start_component()` no longer fails if *keyfile* is
+not ``None``.