diff --git a/05-cache/cache.tex b/05-cache/cache.tex
index 7a6ac56be8f106ad743595cdcba446ab47af6693..c4afb1917945311a577ef1b50df0a86b54fd2b59 100644
--- a/05-cache/cache.tex
+++ b/05-cache/cache.tex
@@ -370,7 +370,7 @@ $C-1$ cached blocks from the previous epoch. When it needs to access the remaini
 block, it replaces the one block, which is not going to be accessed in the current
 epoch. Thus it has only one cache miss per $C$~requests.
 
-Except for the first epoch, the ratio between $\Clru$ and~$\Copt$ is exactly~$C$.
+Except for the first epoch, the ratio between $\Tlru$ and~$\Topt$ is exactly~$C$.
 The first epoch can decrease this ratio, but its effect can be diminished
 by increasing~$K$.
 \qed