diff --git a/utils.rkt b/utils.rkt
index d195730..d91838d 100644
--- a/utils.rkt
+++ b/utils.rkt
@@ -23,6 +23,7 @@
 ;;;     (auto-hash-ref/explicit (ht a b) (+ a (* 2 b))))
 ;;; 5
 ;;;
+;;; Note that only one expression can be supplied in the body.
 (define-syntax (auto-hash-ref/explicit stx)
   (syntax-parse stx
     [(_ (ht:id xs:id ...) body:expr)
@@ -40,6 +41,8 @@
 ;;;
 ;;; Note that the symbol :a is matched to the key 'a in the hash
 ;;; table.
+;;;
+;;; Note that only one expression can be supplied in the body.
 (define-syntax (auto-hash-ref/: stx)
   (syntax-parse stx
     [(_ ht:id body)