diff --git a/src/microstructpy/geometry/ellipsoid.py b/src/microstructpy/geometry/ellipsoid.py
index 220bf425..d767e0d3 100644
--- a/src/microstructpy/geometry/ellipsoid.py
+++ b/src/microstructpy/geometry/ellipsoid.py
@@ -718,7 +718,7 @@ def approximate(self, x1=None):
     def plot(self, **kwargs):
         """Plot the ellipsoid.
 
-        This function uses the :meth:`mpl_toolkits.mplot3d.Axes3D.plot_surface`
+        This function uses the :meth:`mpl_toolkits.mplot3d.axes3d.Axes3D.plot_surface`
         method to add an ellipsoid to the current axes. The keyword arguments
         are passes through to the plot_surface function.
 
diff --git a/src/microstructpy/geometry/sphere.py b/src/microstructpy/geometry/sphere.py
index 38e2d8e3..a2dd3c5d 100644
--- a/src/microstructpy/geometry/sphere.py
+++ b/src/microstructpy/geometry/sphere.py
@@ -152,7 +152,7 @@ def volume_expectation(cls, **kwargs):
     def plot(self, **kwargs):
         """Plot the sphere.
 
-        This function uses the :meth:`mpl_toolkits.mplot3d.Axes3D.plot_surface`
+        This function uses the :meth:`mpl_toolkits.mplot3d.axes3d.Axes3D.plot_surface`
         method to add the sphere to the current axes. The keyword arguments
         are passed through to plot_surface.