diff --git a/doc/eval.rst b/doc/eval.rst
index 9c1192f74246401313d2f55dece966af8b94c9c9..d73959d8068bee1af305d5c5da67dea67a451717 100644
--- a/doc/eval.rst
+++ b/doc/eval.rst
@@ -9,4 +9,4 @@ Visualization of Potentials
 Differentiation of Potentials
 -----------------------------
 
-.. automodule:: sumpy.pde_check
+.. automodule:: sumpy.point_calculus
diff --git a/sumpy/point_calculus.py b/sumpy/point_calculus.py
index 6117002fb93562dab11f1240e55f5d86006cd4be..a47dbebaf1be74a1c0f028a95e4491d580752198 100644
--- a/sumpy/point_calculus.py
+++ b/sumpy/point_calculus.py
@@ -26,7 +26,7 @@ import numpy as np
 import numpy.linalg as la
 from pytools import memoize_method
 
-___doc___ = """
+__doc__ = """
 .. autoclass:: CalculusPatch
 """
 
diff --git a/sumpy/visualization.py b/sumpy/visualization.py
index 7c8737bfc9b8a94598eeb0df035b896b0a8993c3..7765a6e281a10cd7d0da6fdc1ce94d98ba7f92ec 100644
--- a/sumpy/visualization.py
+++ b/sumpy/visualization.py
@@ -23,7 +23,7 @@ THE SOFTWARE.
 """
 
 
-___doc___ = """
+__doc__ = """
 .. autoclass:: FieldPlotter
 """
 
@@ -62,7 +62,7 @@ def separate_by_real_and_imag(data, real_only):
                 yield (name, field)
 
 
-class FieldPlotter:
+class FieldPlotter(object):
     """
     .. automethod:: set_matplotlib_limits
     .. automethod:: show_scalar_in_matplotlib