diff --git a/ChangeLog b/ChangeLog
index a32622e4e9c..0a6b4f9b8de 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2014-03-05  Glenn Morris  <rgm@gnu.org>
+
+	* configure.ac: Tweak the "unported" error message.
+
 2014-03-05  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Fix configuration bug on Solaris 2.5.1 (Bug#16905).
diff --git a/configure.ac b/configure.ac
index f2a2186403c..8b939430c99 100644
--- a/configure.ac
+++ b/configure.ac
@@ -653,7 +653,8 @@ fi
 dnl quotation ends
 
 if test $unported = yes; then
-  AC_MSG_ERROR([Emacs hasn't been ported to `${canonical}' systems.
+  AC_MSG_ERROR([Emacs does not support building on `${canonical}' systems.
+If you think it should, please send a report to bug-gnu-emacs@gnu.org.
 Check `etc/MACHINES' for recognized configuration names.])
 fi