diff --git a/src/werkzeug/datastructures.py b/src/werkzeug/datastructures.py
index 8ff359744..1c7b27da6 100644
--- a/src/werkzeug/datastructures.py
+++ b/src/werkzeug/datastructures.py
@@ -355,6 +355,12 @@ def __setstate__(self, value):
         dict.clear(self)
         dict.update(self, value)
 
+    def __iter__(self):
+        # Work around https://bugs.python.org/issue43246.
+        # (`return super().__iter__()` also works here, which makes this look
+        # even more like it should be a no-op, yet it isn't.)
+        return dict.__iter__(self)
+
     def __getitem__(self, key):
         """Return the first data value for this key;
         raises KeyError if not found.
diff --git a/tests/test_datastructures.py b/tests/test_datastructures.py
index 7249faa8f..c940ae85b 100644
--- a/tests/test_datastructures.py
+++ b/tests/test_datastructures.py
@@ -70,6 +70,14 @@ def create_instance(module=None):
             ud[b"newkey"] = b"bla"
             assert ud != d
 
+    def test_multidict_dict_interop(self):
+        # This would have caught the regression in Werkzeug 2.0.0rc1
+        # (see https://github.com/pallets/werkzeug/pull/2043).
+        md = self.storage_class([("a", 1), ("a", 2)])
+        assert dict(md)["a"] != [1, 2]
+        assert dict(md)["a"] == 1
+        assert dict(md) == {**md} == {"a": 1}
+
     def test_basic_interface(self):
         md = self.storage_class()
         assert isinstance(md, dict)