diff --git a/requirements/base.txt b/requirements/base.txt
index 515470b..614d435 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -1 +1 @@
-simplejson==3.17.6
+simplejson==3.17.2
diff --git a/tests/test_lambda_runtime_marshaller.py b/tests/test_lambda_runtime_marshaller.py
index eeb2715..eb8b848 100644
--- a/tests/test_lambda_runtime_marshaller.py
+++ b/tests/test_lambda_runtime_marshaller.py
@@ -42,4 +42,6 @@ def test_to_json_unicode_encoding(self):
         response = to_json({"price": "£1.00"})
         self.assertEqual('{"price": "£1.00"}', response)
         self.assertNotEqual('{"price": "\\u00a31.00"}', response)
-        self.assertEqual(19, len(response.encode('utf-8')))  # would be 23 bytes if a unicode escape was returned
+        self.assertEqual(
+            19, len(response.encode("utf-8"))
+        )  # would be 23 bytes if a unicode escape was returned