diff --git a/tools/README b/tools/README
index 853ae50c6b..94e69b917c 100644
--- a/tools/README
+++ b/tools/README
@@ -24,6 +24,7 @@ eam_generate	       2nd tool to generate EAM alloy potential files
 eff		       scripts for working with the eFF (electron force field)
 emacs		       add-ons to EMACS editor for editing LAMMPS input scripts
 fep		       scripts for free-energy perturbation with USER-FEP pkg
+i-pi                   Python wrapper for performing path-integral MD (PIMD)
 ipp		       input pre-processor Perl tool for creating input scripts
 lmp2arc		       convert LAMMPS output to Accelrys Insight format
 lmp2cfg		       convert LAMMPS output to CFG files for AtomEye viz