diff --git a/setup.cfg b/setup.cfg
index 6f170ee..5d9f352 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -78,6 +78,3 @@ ignore =
 
 [aliases]
 test = pytest
-
-[tool:pytest]
-collect_ignore = ['setup.py']
diff --git a/yt_idv/opengl_support.py b/yt_idv/opengl_support.py
index 4fe0ecf..0d37647 100644
--- a/yt_idv/opengl_support.py
+++ b/yt_idv/opengl_support.py
@@ -15,10 +15,10 @@
 
 from contextlib import ExitStack, contextmanager
 
-import matplotlib.cm as cm
 import numpy as np
 import traitlets
 import traittypes
+from matplotlib import colormaps as cm
 from OpenGL import GL
 
 # Set up a mapping from numbers to names
diff --git a/yt_idv/shader_objects.py b/yt_idv/shader_objects.py
index 6485ff6..654707b 100644
--- a/yt_idv/shader_objects.py
+++ b/yt_idv/shader_objects.py
@@ -264,7 +264,7 @@ class Shader(traitlets.HasTraits):
         GLValue(),
         default_value=("none", "none", "none", "none"),
     )
-    preprocessor_defs = traitlets.List(trait=traitlets.Tuple)
+    preprocessor_defs = traitlets.List(trait=traitlets.Tuple())
 
     def _get_source(self, source):
         if ";" in source: