--- idris-1.3.1/docs/conf.py~	2018-10-23 17:40:50.000000000 +0800
+++ idris-1.3.1/docs/conf.py	2019-03-03 14:45:33.520932829 +0800
@@ -33,7 +33,7 @@
 # ones.
 extensions = [
     'sphinx.ext.todo',
-    'sphinx.ext.pngmath', # imgmath is not supported on readthedocs.
+    'sphinx.ext.imgmath', # imgmath is not supported on readthedocs.
     'sphinx.ext.ifconfig',
 ]