diff --git a/mcutils.py b/mcutils.py
index 8ceaf4f..8fdbcdf 100644
--- a/mcutils.py
+++ b/mcutils.py
@@ -38,13 +38,15 @@ def colormap( list_of_colors ):
   cmap = LinearSegmentedColormap.from_list('cmap',c,256)
   return cmap
 
-def simpleaxis(ax=plt.gca()):
+def simpleaxis(ax=None):
+    is ax is None: ax = plt.gca()
     ax.spines['top'].set_visible(False)
     ax.spines['right'].set_visible(False)
     ax.get_xaxis().tick_bottom()
     ax.get_yaxis().tick_left()
 
-def noaxis(ax=plt.gca()):
+def noaxis(ax=None):
+    is ax is None: ax = plt.gca()
     ax.spines['top'].set_visible(False)
     ax.spines['right'].set_visible(False)
     ax.spines['left'].set_visible(False)