diff --git a/source/text.tex b/source/text.tex
index f8e942ea4c..bf7ab8d836 100644
--- a/source/text.tex
+++ b/source/text.tex
@@ -271,6 +271,11 @@
 \tcode{value} is set to the parsed value,
 after rounding according to \tcode{round_to_nearest}\iref{round.style}, and
 the member \tcode{ec} is value-initialized.
+\begin{note}
+If the parsed value is too small to be represented,
+\tcode{ec} is value-initialized and
+\tcode{value} is set to a zero with the same sign as the parsed value before rounding.
+\end{note}
 
 \indexlibraryglobal{from_chars}%
 \begin{itemdecl}