diff --git a/upath/core.py b/upath/core.py
index 90ebac60..6e35e208 100644
--- a/upath/core.py
+++ b/upath/core.py
@@ -1880,7 +1880,7 @@ def unlink(self, missing_ok: bool = False) -> None:
             return
         self.fs.rm(self.path, recursive=False)
 
-    def rmdir(self, recursive: bool = True) -> None:  # fixme: non-standard
+    def rmdir(self, recursive: bool = UNSET_DEFAULT) -> None:  # fixme: non-standard
         """
         Remove this directory.
 
@@ -1890,13 +1890,26 @@ def rmdir(self, recursive: bool = True) -> None:  # fixme: non-standard
         as it supports a `recursive` parameter to remove non-empty
         directories and defaults to recursive deletion.
 
-        This behavior is likely to change in future releases once
-        `.delete()` is introduced.
+        Removing a non-empty directory without passing `recursive`
+        raises a FutureWarning: in universal-pathlib 0.4.0 the default
+        becomes non-recursive, matching pathlib.Path.rmdir(), and
+        `.delete()` will remove a directory and its contents.
 
         """
         if not self.is_dir():
             raise NotADirectoryError(str(self))
-        if not recursive and next(self.iterdir()):  # type: ignore[arg-type]
+        if recursive is UNSET_DEFAULT:
+            recursive = True
+            if next(self.iterdir(), None) is not None:
+                warnings.warn(
+                    f"{type(self).__name__}.rmdir() currently removes a non-empty"
+                    " directory and its contents. In universal-pathlib 0.4.0 it will"
+                    " raise, like pathlib.Path.rmdir() does. Pass recursive=True to"
+                    " keep removing the contents.",
+                    FutureWarning,
+                    stacklevel=2,
+                )
+        elif not recursive and next(self.iterdir(), None) is not None:
             raise OSError(f"Not recursive and directory not empty: {self}")
         self.fs.rm(self.path, recursive=recursive)
 
diff --git a/upath/implementations/cloud.py b/upath/implementations/cloud.py
index 0f76b4c1..984fd97c 100644
--- a/upath/implementations/cloud.py
+++ b/upath/implementations/cloud.py
@@ -216,7 +216,10 @@ def root(self) -> str:
     def iterdir(self) -> Iterator[Self]:
         try:
             yield from super().iterdir()
-        except NotImplementedError:
+        except (NotImplementedError, ValueError):
+            # listing a namespace (e.g. a user's repositories) is unsupported:
+            # older huggingface_hub raises NotImplementedError, newer versions
+            # reject the single-segment repository id with a ValueError
             raise UnsupportedOperation
 
     def touch(self, mode: int = 0o666, exist_ok: bool = True) -> None:
diff --git a/upath/tests/cases.py b/upath/tests/cases.py
index 22587fa9..8597f46d 100644
--- a/upath/tests/cases.py
+++ b/upath/tests/cases.py
@@ -962,6 +962,19 @@ def test_rmdir_not_empty(self):
         with pytest.raises(OSError, match="not empty"):
             p.rmdir(recursive=False)
 
+    def test_rmdir_not_empty_warns_about_the_future_default(self):
+        p = self.path.joinpath("folder1")
+        with pytest.warns(FutureWarning, match="0.4.0"):
+            p.rmdir()
+        assert not p.exists()
+
+    def test_rmdir_not_empty_recursive_does_not_warn(self):
+        p = self.path.joinpath("folder1")
+        with warnings.catch_warnings():
+            warnings.simplefilter("error", FutureWarning)
+            p.rmdir(recursive=True)
+        assert not p.exists()
+
     def test_fsspec_compat(self):
         fs = self.path.fs
         content = b"a,b,c\n1,2,3\n4,5,6"
diff --git a/upath/tests/test_extensions.py b/upath/tests/test_extensions.py
index f29ba999..fafab0c0 100644
--- a/upath/tests/test_extensions.py
+++ b/upath/tests/test_extensions.py
@@ -79,6 +79,15 @@ def test_is_not_wrapped_class(self):
     def test_chmod(self):
         self.path.joinpath("file1.txt").chmod(777)
 
+    @overrides_base
+    def test_rmdir_not_empty_warns_about_the_future_default(self):
+        # wrapping a pathlib.Path, whose rmdir() already raises on a
+        # non-empty directory: there is no future change to warn about
+        p = self.path.joinpath("folder1")
+        with pytest.raises(OSError):
+            p.rmdir()
+        assert p.exists()
+
     @overrides_base
     @pytest.mark.skipif(
         sys.version_info < (3, 12), reason="storage options only handled in 3.12+"