diff --git a/app/views/wiki/tex.rhtml b/app/views/wiki/tex.rhtml
index 0fd6d0bc..d1d6a733 100644
--- a/app/views/wiki/tex.rhtml
+++ b/app/views/wiki/tex.rhtml
@@ -109,6 +109,8 @@
 \re@DeclareMathSymbol{\Perp}{\mathrel}{symbolsC}{121}
 \re@DeclareMathSymbol{\Vbar}{\mathrel}{symbolsC}{121}
 \re@DeclareMathSymbol{\sslash}{\mathrel}{stmry}{12}
+\re@DeclareMathSymbol{\invamp}{\mathrel}{symbolsC}{77}
+\re@DeclareMathSymbol{\parr}{\mathrel}{symbolsC}{77}
 \makeatother
 
 % Widecheck