diff --git a/source/intro.tex b/source/intro.tex
index 55a4e8e783..ac34c8c1cd 100644
--- a/source/intro.tex
+++ b/source/intro.tex
@@ -303,7 +303,7 @@
 issuance of a diagnostic message). Many erroneous program constructs do
 not engender undefined behavior; they are required to be diagnosed.
 Evaluation of a constant expression never exhibits behavior explicitly
-specified as undefined\iref{expr.const}.
+specified as undefined in \ref{intro} through \ref{cpp} of this document\iref{expr.const}.
 \end{defnote}
 
 \indexdefn{behavior!unspecified}%