diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..31d8275
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+	"python.linting.pylintEnabled": true
+}
diff --git a/json5/lib.py b/json5/lib.py
index a7f6084..aa1fef1 100644
--- a/json5/lib.py
+++ b/json5/lib.py
@@ -19,7 +19,6 @@
 
 from .parser import Parser
 
-
 if sys.version_info[0] < 3:
     str_types = (str, unicode)
     str = unicode  # pylint: disable=redefined-builtin, invalid-name
@@ -290,7 +289,6 @@ def _dumps(obj, skipkeys, ensure_ascii, check_circular, allow_nan, indent,
 
     item_sep, kv_sep = separators
     item_sep += indent_str
-    level += 1
 
     if seen is not None:
         i = id(obj)
@@ -306,17 +304,22 @@ def _dumps(obj, skipkeys, ensure_ascii, check_circular, allow_nan, indent,
                        check_circular, allow_nan, indent,
                        separators, default, sort_keys,
                        quote_keys, trailing_commas,
-                       allow_duplicate_keys, seen, level,
+                       allow_duplicate_keys, seen, level + 1,
                        item_sep, kv_sep, indent_str, end_str)
     elif hasattr(obj, '__getitem__') and hasattr(obj, '__iter__'):
         s = _dump_array(obj, skipkeys, ensure_ascii,
                         check_circular, allow_nan, indent,
                         separators, default, sort_keys,
                         quote_keys, trailing_commas,
-                        allow_duplicate_keys, seen, level,
+                        allow_duplicate_keys, seen, level + 1,
                         item_sep, indent_str, end_str)
     else:
-        s = default(obj)
+        s = _dumps(default(obj), skipkeys, ensure_ascii,
+                   check_circular, allow_nan, indent,
+                   separators, default, sort_keys,
+                   quote_keys, trailing_commas,
+                   allow_duplicate_keys, seen, level,
+                   is_key)[1]
 
     if seen is not None:
         seen.remove(i)
diff --git a/tests/lib_test.py b/tests/lib_test.py
index ba6b64e..f978650 100644
--- a/tests/lib_test.py
+++ b/tests/lib_test.py
@@ -18,7 +18,6 @@
 import os
 import sys
 import unittest
-
 from collections import OrderedDict
 from string import printable
 
@@ -28,7 +27,6 @@
     # Make the `hypothesis` library optional, so that the other tests will
     # still run if it isn't installed.
     import hypothesis.strategies as some
-
     from hypothesis import given
 
     some_json = some.recursive(
@@ -375,7 +373,7 @@ def _custom_serializer(obj):
 
         self.assertRaises(TypeError, json5.dumps, set())
         self.assertEqual(json5.dumps(set(), default=_custom_serializer),
-                         'something')
+                         '"something"')
 
     def test_ensure_ascii(self):
         self.check(u'\u00fc', '"\\u00fc"')