diff --git a/derivative/differentiation.py b/derivative/differentiation.py
index e633c68..dbf8657 100644
--- a/derivative/differentiation.py
+++ b/derivative/differentiation.py
@@ -248,7 +248,10 @@ def _restore_axes(dX: NDArray, axis: int, orig_shape: tuple[int, ...]) -> NDArra
         return dX.flatten()
     else:
         # order of operations coupled with _align_axes
-        extra_dims = tuple(length for ax, length in enumerate(orig_shape) if ax != axis)
+        orig_diff_axis = range(len(orig_shape))[axis] # to handle negative axis args
+        extra_dims = tuple(
+            length for ax, length in enumerate(orig_shape) if ax != orig_diff_axis
+        )
         moved_shape = (orig_shape[axis],) + extra_dims
         dX = np.moveaxis(dX.T.reshape((moved_shape)), 0, axis)
         return dX
diff --git a/derivative/utils.py b/derivative/utils.py
index 707f866..616c88c 100644
--- a/derivative/utils.py
+++ b/derivative/utils.py
@@ -10,7 +10,11 @@
 else:
     from importlib.metadata import entry_points
 
-hyperparam_algorithms = entry_points(group="derivative.hyperparam_opt")
+try:
+	hyperparam_algorithms = entry_points(group="derivative.hyperparam_opt")
+except TypeError as exc:
+	import sys
+	raise TypeError(f"Oops, no 'group' kwarg.  function imported from {entry_points.__module__}")
 
 
 def _load_hyperparam_func(func_key):
diff --git a/pyproject.toml b/pyproject.toml
index 238ebce..5e8e4f2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "derivative"
-version = "0.6.1"
+version = "0.6.2"
 description = "Numerical differentiation in python."
 repository = "https://github.com/andgoldschmidt/derivative"
 documentation = "https://derivative.readthedocs.io/"
@@ -20,6 +20,9 @@ numpy = "^1.18.3"
 scipy = "^1.4.1"
 scikit-learn = "^1"
 
+# third-party access to the functionality of importlib.metadata
+importlib-metadata = "^7.1.0"
+
 # docs
 sphinx = {version = "^5", optional = true}
 nbsphinx = {version = "^0.6.1", optional = true}
@@ -32,12 +35,12 @@ matplotlib = {version = "^3.2.1", optional = true}
 pytest = {version = "^7", optional = true}
 
 [tool.poetry.extras]
-docs = ["sphinx", "nbsphinx", "ipykernel", "jupyter_client", "matplotlib", "pandoc"]
+docs = ["sphinx", "nbsphinx", "ipykernel", "jupyter_client", "matplotlib"]
 dev = ["pytest"]
 
 [build-system]
 requires = ["poetry-core>=1.1.0"]
 build-backend = "poetry.core.masonry.api"
 
-[tool.poetry.plugins.'derivative.hyperparam_opt']
+[tool.poetry.plugins."derivative.hyperparam_opt"]
 "kalman.default" = "derivative.utils:_default_kalman"
diff --git a/tests/test_interface.py b/tests/test_interface.py
index 49a88fc..b70c7f8 100644
--- a/tests/test_interface.py
+++ b/tests/test_interface.py
@@ -98,4 +98,12 @@ def test_hyperparam_entrypoint():
     func = utils._load_hyperparam_func("kalman.default")
     expected = 1
     result = func(None, None)
-    assert result == expected
\ No newline at end of file
+    assert result == expected
+
+
+def test_negative_axis():
+    t = np.arange(3)
+    x = np.ones((2, 3, 2))
+    axis = -2
+    dx = dxdt(x, t, kind='finite_difference', axis=axis, k=1)
+    assert x.shape == dx.shape
\ No newline at end of file