--- a/doc/conf.py
+++ b/doc/conf.py
@@ -42,7 +42,6 @@ sys.path.append(os.path.abspath('sphinxe
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = ['sphinx.ext.todo',
-              'sphinx.ext.imgmath',
               'sphinx.ext.inheritance_diagram',
               'sphinx.ext.graphviz',
               'sphinx.ext.autodoc',
@@ -55,6 +54,11 @@ extensions = ['sphinx.ext.todo',
               #'IPython.sphinxext.ipython_directive',
               #'IPython.sphinxext.ipython_console_highlighting'
               ]
+try:
+   import sphinx.ext.imgmath
+   extensions.append('sphinx.ext.imgmath')
+except:
+   pass
 on_rtd = os.environ.get('READTHEDOCS') == 'True'
 if on_rtd:
     extensions.append('readthedocs_ext.readthedocs')
