diff --git a/src/cltools/Benchmark.cpp b/src/cltools/Benchmark.cpp
index afae904df5..cfdec413f3 100644
--- a/src/cltools/Benchmark.cpp
+++ b/src/cltools/Benchmark.cpp
@@ -445,7 +445,7 @@ PLUMED_REGISTER_CLTOOL(Benchmark,"benchmark")
 
 void Benchmark::registerKeywords( Keywords& keys ) {
   CLTool::registerKeywords( keys );
-  keys.add("compulsory","--plumed","plumed.dat","convert the input in this file to the html manual");
+  keys.add("compulsory","--plumed","plumed.dat","colon separated path(s) to the input file(s)");
   keys.add("compulsory","--kernel","this","colon separated path(s) to kernel(s)");
   keys.add("compulsory","--natoms","100000","the number of atoms to use for the simulation");
   keys.add("compulsory","--nsteps","2000","number of steps of MD to perform (-1 means forever)");