diff --git a/constants/33a.md b/constants/33a.md
index 206694f..872e7d3 100644
--- a/constants/33a.md
+++ b/constants/33a.md
@@ -1,8 +1,8 @@
-# Ihara constant over $\mathbf{F}_2$
+# Ihara constant over $\mathbf{F}\_2$
 
 ## Description of constant
 
-$C_{33}=A(2)$ is the **Ihara constant** over $\mathbb{F}_2$.
+$C\_{33}=A(2)$ is the **Ihara constant** over $\mathbb{F}\_{2}$.
 <a href="#DM2013-def-Aq">[DM2013-def-Aq]</a>
 
 For each integer $g\ge 1$, let