diff --git a/ovgenpy/config.py b/ovgenpy/config.py
index 0fdae17..d418745 100644
--- a/ovgenpy/config.py
+++ b/ovgenpy/config.py
@@ -2,6 +2,7 @@ from io import StringIO
 from typing import ClassVar
 
 from ovgenpy.utils.keyword_dataclasses import dataclass, fields
+# from dataclasses import dataclass, fields
 from ruamel.yaml import yaml_object, YAML
 
 
@@ -92,6 +93,7 @@ class _ConfigMixin:
             value = getattr(self, key)
             typ = field.type
 
+            # FIXME crashes on generics, https://github.com/Stewori/pytypes ?
             if not isinstance(value, typ):
                 name = type(self).__name__
                 raise OvgenError(f'{name}.{key} was supplied {repr(value)}, should be of type {typ.__name__}')
diff --git a/ovgenpy/renderer.py b/ovgenpy/renderer.py
index f15c127..ca14a36 100644
--- a/ovgenpy/renderer.py
+++ b/ovgenpy/renderer.py
@@ -94,7 +94,8 @@ class MatplotlibRenderer:
         # Create Axes
         # https://matplotlib.org/api/_as_gen/matplotlib.pyplot.subplots.html
         if self.fig:
-            plt.close(self.fig)     # FIXME
+            raise Exception("I don't currently expect to call set_layout() twice")
+            plt.close(self.fig)
 
         axes2d: np.ndarray['Axes']
         self.fig, axes2d = plt.subplots(