diff --git a/sandbox/grist/functions/info.py b/sandbox/grist/functions/info.py
index 99ab6424..a230af30 100644
--- a/sandbox/grist/functions/info.py
+++ b/sandbox/grist/functions/info.py
@@ -740,12 +740,12 @@ class Response(object):
   """
   Similar to the Response class from the `requests` library.
   """
-  def __init__(self, content, status, statusText, headers, encoding):
+  def __init__(self, content, status, statusText, headers, encoding=None):
     self.content = content  # raw bytes
     self.status_code = status  # e.g. 404
     self.reason = statusText  # e.g. "Not Found"
     self.headers = CaseInsensitiveDict(headers)
-    self.encoding = encoding or self.apparent_encoding
+    self.encoding = encoding or self.apparent_encoding or "utf-8"
 
   @property
   def text(self):
diff --git a/sandbox/grist/test_requests.py b/sandbox/grist/test_requests.py
index d5960f6b..86c4cfd3 100644
--- a/sandbox/grist/test_requests.py
+++ b/sandbox/grist/test_requests.py
@@ -73,6 +73,13 @@ class TestResponse(unittest.TestCase):
     self.assertEqual(r.content, content)
     self.assertEqual(r.text, text)
 
+  def test_unknown_undetectable_encoding(self):
+    content = b''
+    r = Response(content, 200, "OK", {}, encoding=None)
+
+    # Not knowing the encoding should not break text
+    self.assertEqual(r.text, "")
+
 
 class TestRequestsPostInterface(unittest.TestCase):
     def test_no_post_args(self):