diff --git a/ch04.asciidoc b/ch04.asciidoc
index d9d0f936..f117042b 100644
--- a/ch04.asciidoc
+++ b/ch04.asciidoc
@@ -120,6 +120,7 @@ Elliptic curve multiplication is a type of function that cryptographers call a "
 <<ecc-curve>> is an example of an elliptic curve, similar to that used by bitcoin.
 
 [[ecc-curve]]
+[role="smallerfourty"]
 .An elliptic curve
 image::images/mbc2_0402.png["ecc-curve"]