diff --git a/CHANGES/v2.4.md b/CHANGES/v2.4.md
index e49ff64e6014f01812c5dce4fd5b483b1a8145ef..58d842bede4dcd38d4dd61d3d2f4202946ed6802 100644
--- a/CHANGES/v2.4.md
+++ b/CHANGES/v2.4.md
@@ -1,6 +1,6 @@
 @page CHANGES-2-4 Version 2.4
 
-## Version 2.4 (Oct 3, 2017)
+## Version 2.4b (Oct 3, 2017)
 
 Version 2.4 contains several improvements with respect to 2.3. Users currently working with 2.3
 should have a look at the section "Changes leading to incompatible behavior" below and
diff --git a/VERSION b/VERSION
index c0fcc94f47e0d9a2ffeca486acab3641212d3b42..817aa2df05c740f0de2e4b0909934aaa0c1c9c69 100644
--- a/VERSION
+++ b/VERSION
@@ -5,4 +5,4 @@
 # (this is same as gromacs)
 # Notice that "plumed --version" will return only 2.X
 # and "plumed --long-version" will return the full string
-2.4.0
+2.4.0b