We need one patch on top of 0.3.8 for compatibility with Werkzeug 1.0.

Taken from upstream:
https://github.com/flask-restful/flask-restful/commit/73376a488907af3042b52678ac4c23f8a8911e5b

diff --git a/tests/test_api.py b/tests/test_api.py
index f7f8e661..6795d362 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -445,7 +445,9 @@ def test_handle_non_api_error(self):
 
         resp = app.get("/foo")
         self.assertEquals(resp.status_code, 404)
-        self.assertEquals('text/html', resp.headers['Content-Type'])
+        # in newer versions of werkzeug this is `text/html; charset=utf8`
+        content_type, _, _ = resp.headers['Content-Type'].partition(';')
+        self.assertEquals('text/html', content_type)
 
     def test_non_api_error_404_catchall(self):
         app = Flask(__name__)
diff --git a/tests/test_reqparse.py b/tests/test_reqparse.py
index 2f1fbedf..9776f17c 100644
--- a/tests/test_reqparse.py
+++ b/tests/test_reqparse.py
@@ -2,9 +2,9 @@
 import unittest
 from mock import Mock, patch
 from flask import Flask
-from werkzeug import exceptions, MultiDict
+from werkzeug import exceptions
 from werkzeug.wrappers import Request
-from werkzeug.datastructures import FileStorage
+from werkzeug.datastructures import FileStorage, MultiDict
 from flask_restful.reqparse import Argument, RequestParser, Namespace
 import six
 import decimal
uix/diff/po/packages/fr.po?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/po/packages/fr.po'>
<input type='hidden' name='id' value='c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'>root</a>/<a href='/guix/log/po?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'>po</a>/<a href='/guix/log/po/packages?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'>packages</a>/<a href='/guix/log/po/packages/fr.po?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81'>fr.po</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/po/packages/fr.po?id=c93c7af1cef08ae0a0aeccf3e3c0af188abddc81&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-12-04 19:40:52 +0100'>2021-12-04</span></td><td><a href='/guix/commit/po/packages/fr.po?id=7fcb20a8fa242ab53b9bc97ef0b0367c6a399bd4'>nls: Update translations.</a></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-11-06 14:06:36 +0100'>2021-11-06</span></td><td><a href='/guix/commit/po/packages/fr.po?id=85430a9ea6f32aaae3e34741e292a01a2de62ee0'>nls: Update translations.</a><span class='msg-avail'>...<span class='msg-tooltip'>* po/doc/guix-cookbook.es.po: New file.
* po/doc/local.mk: Add 'es' cookbook.
* doc/local.mk: Add 'es' cookbook.
</span></span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-10-17 22:10:25 +0200'>2021-10-17</span></td><td><a href='/guix/commit/po/packages/fr.po?id=15c91189cb61c579f4289047c79530cefe75215f'>nls: Update translations.</a></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-09-02 04:06:52 +0200'>2021-09-02</span></td><td><a href='/guix/commit/po/packages/fr.po?id=1ff2092a39dc5c7c7cd9b4a0ba4b59f92e738efc'>nls: Update translations.</a><span class='msg-avail'>...<span class='msg-tooltip'>* po/packages/it.po: New file.
* po/packages/LINGUAS: Add `it'.
* po/*/*.po: Update translations.
</span></span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-08-04 14:49:53 +0200'>2021-08-04</span></td><td><a href='/guix/commit/po/packages/fr.po?id=6c10c96fedf707d7be059aeb79bd5c8e2d2fa210'>nls: Update translations.</a><span class='msg-avail'>...<span class='msg-tooltip'>* po/doc/guix-cookbook.ru.po: New file.
* po/doc/guix-cookbook.sk.po: New file.
* po/*/*.po: Update translations.
* doc/local.mk (COOKBOOK_LANGUAGES): Add ru and sk.
(info_TEXINFOS): Add Russian and Slovak cookbooks.
* po/doc/local.mk (DOC_COOKBOOK_PO_FILES): Add Russian and Slovak po
files.
</span></span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-05-10 22:34:43 -0400'>2021-05-10</span></td><td><a href='/guix/commit/po/packages/fr.po?id=21fcced608c93e1ac836cdd9ab8c5d200c667e75'>nls: Update translations.</a></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-04-18 13:17:35 +0200'>2021-04-18</span></td><td><a href='/guix/commit/po/packages/fr.po?id=5ebe6904ea3881029e41147f49981ec2bd5f6cc7'>nls: Update 'fr' translations.</a></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-01-28 16:41:18 +0100'>2021-01-28</span></td><td><a href='/guix/commit/po/packages/fr.po?id=a00af779047d92c0c0b4817b870bcae7fd610259'>nls: Update 'fr' translation.</a></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2020-11-09 00:14:17 +0100'>2020-11-09</span></td><td><a href='/guix/commit/po/packages/fr.po?id=f0ad0e85cdae95df17b2f66fec97fcf0a4e70a0b'>nls: Update 'fr' translations.</a></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2020-10-27 00:40:24 +0100'>2020-10-27</span></td><td><a href='/guix/commit/po/packages/fr.po?id=b35550c3d8ab5db3210319269ef5ad1dd271a43a'>nls: Update.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-10-16 15:00:49 +0200'>2020-10-16</span></td><td><a href='/guix/commit/po/packages/fr.po?id=a743b04a41b9976a8d087056393ba5cf317af452'>nls: Update.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-04-14 13:01:58 +0200'>2020-04-14</span></td><td><a href='/guix/commit/po/packages/fr.po?id=2b2921937017bf4b3c7c8be2d0448f8c64d02bb1'>nls: Update.</a></td><td>Ludovic Courtès</td></tr>