diff --git a/book/src/design/gadgets.md b/book/src/design/gadgets.md
index a4bab168..4eaaa087 100644
--- a/book/src/design/gadgets.md
+++ b/book/src/design/gadgets.md
@@ -1,3 +1,7 @@
 # Gadgets
 
-In this section we document the gadgets and chip designs provided by halo2.
+In this section we document some example gadgets and chip designs that are suitable for
+Halo 2.
+
+> Neither these gadgets, nor their implementations, have been reviewed, and they should
+> not be used in production.