diff --git a/lispref/ChangeLog b/lispref/ChangeLog
index dab200a059a..7619d6fe2c6 100644
--- a/lispref/ChangeLog
+++ b/lispref/ChangeLog
@@ -1,3 +1,9 @@
+2003-12-31  Andreas Schwab  <schwab@suse.de>
+
+	* numbers.texi (Math Functions): sqrt reports a domain-error
+	error.
+	(Float Basics): Use `(/ 0.0 0.0)' instead of `(sqrt -1.0)'.
+
 2003-12-30  Luc Teirlinck  <teirllm@auburn.edu>
 
 	* tips.texi (Documentation Tips): Update item on hyperlinks in
diff --git a/lispref/numbers.texi b/lispref/numbers.texi
index 9c71922c0d0..3a4f4ae75c4 100644
--- a/lispref/numbers.texi
+++ b/lispref/numbers.texi
@@ -172,7 +172,7 @@ to write negative floating point numbers, as in @samp{-1.0}.
 which provides for positive infinity and negative infinity as floating point
 values.  It also provides for a class of values called NaN or
 ``not-a-number''; numerical functions return such values in cases where
-there is no correct answer.  For example, @code{(sqrt -1.0)} returns a
+there is no correct answer.  For example, @code{(/ 0.0 0.0)} returns a
 NaN.  For practical purposes, there's no significant difference between
 different NaN values in Emacs Lisp, and there's no rule for precisely
 which NaN value should be used in a particular case, so Emacs Lisp
@@ -1146,7 +1146,7 @@ integer values.
 
 @defun sqrt arg
 This returns the square root of @var{arg}.  If @var{arg} is negative,
-the value is a NaN.
+it signals a @code{domain-error} error.
 @end defun
 
 @node Random Numbers