diff --git a/doc/frama-c-book.cls b/doc/frama-c-book.cls
index 8587442f5f54d201baabd96f941bcb37dab5fce5..39151e915df0c313cc2bc55ad9a2b1a09a038141 100644
--- a/doc/frama-c-book.cls
+++ b/doc/frama-c-book.cls
@@ -306,7 +306,7 @@
 % --------------------------------------------------------------------------
 
 \titleformat{\chapter}[display]
-  {\sc\Huge}
+  {\sc\huge}
   {\filleft\fontsize{50}{0}\selectfont\thechapter}
   {-1.1em}
   {\filright}