diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index da2c7a66ddf2..fee14941bc88 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-11-21  Ben Elliston  <bje@au.ibm.com>
+
+	* gengtype-lex.l: Enable noinput flex option.
+	(YY_NO_INPUT): Remove define.
+
 2009-11-21  Alexandre Oliva  <aoliva@redhat.com>
 
 	* tree-ssa.c (find_released_ssa_name): Handle NULL wi.
diff --git a/gcc/gengtype-lex.l b/gcc/gengtype-lex.l
index da118d02b28f..297ebf857a80 100644
--- a/gcc/gengtype-lex.l
+++ b/gcc/gengtype-lex.l
@@ -19,6 +19,8 @@ You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
+%option noinput
+
 %{
 #include "bconfig.h"
 #include "system.h"
@@ -28,7 +30,6 @@ along with GCC; see the file COPYING3.  If not see
 
 #include "gengtype.h"
 
-#define YY_NO_INPUT
 #define YY_DECL int yylex (const char **yylval)
 #define yyterminate() return EOF_TOKEN