diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
index 09a1d273a9..0e9351d3cb 100644
--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt
@@ -33,10 +33,13 @@ escaped.
 
 Multiple lines can be added to an option by using the `--add` option.
 If you want to update or unset an option which can occur on multiple
-lines, a POSIX regexp `value-pattern` needs to be given.  Only the
-existing values that match the regexp are updated or unset.  If
-you want to handle the lines that do *not* match the regex, just
-prepend a single exclamation mark in front (see also <<EXAMPLES>>).
+lines, a `value-pattern` (which is an extended regular expression,
+unless the `--fixed-value` option is given) needs to be given.  Only the
+existing values that match the pattern are updated or unset.  If
+you want to handle the lines that do *not* match the pattern, just
+prepend a single exclamation mark in front (see also <<EXAMPLES>>),
+but note that this only works when the `--fixed-value` option is not
+in use.
 
 The `--type=<type>` option instructs 'git config' to ensure that incoming and
 outgoing values are canonicalize-able under the given <type>.  If no