diff --git a/Tests/varLib/interpolatable_test.py b/Tests/varLib/interpolatable_test.py
index 1e4ee9ccf..9eb66ba81 100644
--- a/Tests/varLib/interpolatable_test.py
+++ b/Tests/varLib/interpolatable_test.py
@@ -35,9 +35,9 @@ class InterpolatableTest(unittest.TestCase):
             shutil.rmtree(self.tempdir)
 
     @staticmethod
-    def get_test_input(test_file_or_folder):
+    def get_test_input(*test_file_or_folder):
         path, _ = os.path.split(__file__)
-        return os.path.join(path, "data", test_file_or_folder)
+        return os.path.join(path, "data", *test_file_or_folder)
 
     @staticmethod
     def get_file_list(folder, suffix, prefix=""):
@@ -93,6 +93,15 @@ class InterpolatableTest(unittest.TestCase):
         otf_paths = self.get_file_list(self.tempdir, suffix)
         self.assertIsNone(interpolatable_main(otf_paths))
 
+    def test_interpolatable_varComposite(self):
+        input_path = self.get_test_input(
+            "..", "..", "ttLib", "data", "varc-ac00-ac01.ttf"
+        )
+        # This particular test font which was generated by machine-learning
+        # exhibits an "error" in one of the masters; it's a false-positive.
+        # Just make sure the code runs.
+        interpolatable_main((input_path,))
+
 
 if __name__ == "__main__":
     sys.exit(unittest.main())