diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index ce7d0903d2af4eaa6f21647a103c536b1b950791..4c87a25faebf60c38eb18aa4d01a02bab7177c55 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -361,7 +361,7 @@ int main(int argc, char *argv[]) {
     auto const V0 = parset.get<double>("boundary.friction.V0");
     auto const mu = parset.get<double>("boundary.friction.mu");
     auto const timesteps = parset.get<size_t>("timeSteps");
-    double const tau = parset.get<double>("endOfTime") / timesteps;
+    auto const tau = parset.get<double>("endOfTime") / timesteps;
 
     auto const &dirichletFunction = functions.get("dirichletCondition");
     auto const &neumannFunction = functions.get("neumannCondition");