diff --git a/ChangeLog b/ChangeLog
index bdb132c2..e05c208e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-30  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
+
+	* lexer.l: Replace the old, now-defunct #define YY_NO_UNPUT by
+	the new %option nounput.  This gets rid of a compiler warning.
+
 2012-01-30  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
 
 	Add a connection_type attribute to each programmer, rather than
diff --git a/lexer.l b/lexer.l
index 34f5afc1..103c0829 100644
--- a/lexer.l
+++ b/lexer.l
@@ -35,8 +35,6 @@
 #include "config_gram.h"
 #include "lists.h"
 
-#define YY_NO_UNPUT
-
 %}
 
 DIGIT    [0-9]
@@ -47,6 +45,7 @@ SIGN     [+-]
 %x strng
 %x incl
 %x comment
+%option nounput
 
 /* Bump resources for classic lex. */
 %e2000