diff --git a/doc/supply_demand.rst b/doc/supply_demand.rst
index d90c1fb7..b0692cb5 100644
--- a/doc/supply_demand.rst
+++ b/doc/supply_demand.rst
@@ -11,7 +11,7 @@ Test |H2O|
 
 This is a test
 
-\ce{(2Na+,SO4^2- ) + (Ba^2+, 2Cl- ) -> BaSO4 v + 2NaCl}
+.. math:: \ce{(2Na+,SO4^2- ) + (Ba^2+, 2Cl- ) -> BaSO4 v + 2NaCl}
 
 .. |H2O| replace:: H\ :sub:`2`\ O
 .. |CH4| replace:: CH\ :sub:`4`