diff --git a/regtest/basic/rt-atomic-units/plumed.dat b/regtest/basic/rt-atomic-units/plumed.dat
index 8f8015c6ea880489a29795299b2c76a1cb5686e3..03e6c38942a28ea55eebfe922821912c6c855c08 100644
--- a/regtest/basic/rt-atomic-units/plumed.dat
+++ b/regtest/basic/rt-atomic-units/plumed.dat
@@ -1,4 +1,4 @@
-UNITS LENGTH=Bohr TIME=atomic ENERGY=Hartree
+UNITS LENGTH=Bohr TIME=atomic ENERGY=Ha
 d1_bohr: DISTANCE ATOMS=1,2 NOPBC
 d2_bohr: DISTANCE ATOMS=1,6 NOPBC
 d1_angs: CUSTOM ARG=d1_bohr FUNC=0.52917721067*x PERIODIC=NO
diff --git a/src/tools/Units.cpp b/src/tools/Units.cpp
index 5f15d633c9628c5bc02dfa18d52e4c6e2388849a..345c99973300e5b8f6ed255c58d2a302f200e4e7 100644
--- a/src/tools/Units.cpp
+++ b/src/tools/Units.cpp
@@ -50,8 +50,7 @@ void Units::setEnergy(const std::string &s) {
     energy=0.001;
   } else if(s=="eV") {
     energy=96.48530749925792;
-  } else if(s=="Hartree" || s =="Ha") {
-    energyString="Hartree";
+  } else if(s =="Ha") {
     energy=2625.499638;
   } else {
     energy=-1.0;