diff --git a/filter.tex b/filter.tex
index b9cff89..24c902c 100644
--- a/filter.tex
+++ b/filter.tex
@@ -248,7 +248,7 @@ \subsubsection{Continuous Equations}
 \tau_{22} &= -\mu_d K_h D_{22} 
 \notag \\
 %
-\tau_{33} &= -\mu_d K_v D_{33} 
+\tau_{33} &= -\mu_d K_h D_{33} 
 \notag \\
 %
 \tau_{12} &= -\mu_d K_h D_{12}