diff --git a/CHANGES/v2.1.txt b/CHANGES/v2.1.txt
index cfdca925eecac836211c0957810b596e338d0532..515fcf8d815cd9c8215fd72f33eb28313bfd1f48 100644
--- a/CHANGES/v2.1.txt
+++ b/CHANGES/v2.1.txt
@@ -182,6 +182,7 @@ See <a href="http://github.com/plumed/plumed2/commits/v2.1">branch v2.1 on git r
 
 For users:
 - Updated gromacs patch 5.0 to 5.0.4
+- Fixed bug in \ref ENSEMBLE derivatives
 - Fixed a serious bug in virial communicated from plumed to gromacs, for both gromacs versions 4.6 and 5.0.
   Patch for gromacs 4.5 is not fixed. See notes <a href="http://github.com/plumed/plumed2/issues/132"> here </a>
   This fix requires gromacs to be repatched and could be very important if you run biased simulations in the NPT ensemble.