diff --git a/ChangeLog b/ChangeLog
index c24495c5e..e315b6bff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2006-08-30  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
+	* HACKING: We need Bison 2.3.
+
 	* evtgbaparse/evtgbaparse.yy, ltlparse/ltlparse.yy,
 	tgbaparse/tgbaparse.yy: Fix Bison warnings about unset $$.
 
diff --git a/HACKING b/HACKING
index 2b6669dad..b706bc0f4 100644
--- a/HACKING
+++ b/HACKING
@@ -13,7 +13,7 @@ generally if you plan to regenerate some of the generated files.
   GNU Automake >= 1.9
   GNU Libtool >= 1.4
   GNU Flex (the version seems to matters, we used 2.5.31)
-  GNU Bison == 2.0  (2.1 will not work, but 2.2 is expected to.)
+  GNU Bison >= 2.3
   SWIG >= 1.3.23
   Doxygen >= 1.4.0