diff --git a/docs/src/reading.md b/docs/src/reading.md
index 24de52f..8cc774e 100644
--- a/docs/src/reading.md
+++ b/docs/src/reading.md
@@ -442,7 +442,7 @@ end
 JSON.@choosetype AbstractMonster x -> x.monster_type[] == "vampire" ? Dracula : Werewolf
 
 # Define a custom numeric type with special parsing
-struct Percent <: Number
+@nonstruct struct Percent <: Number
     value::Float64
 end