diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index 3efbab56b6929d498b868f8d40ca8c22b4ad99e9..4493c6540114dd511e71926534fe610457572a1e 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -131,7 +131,7 @@ int main(int argc, char *argv[]) {
     auto const solver_tolerance = parset.get<double>("solver.tolerance");
 
     auto const refinements = parset.get<size_t>("grid.refinements");
-    double const refinement_factor = std::pow(2, refinements);
+    size_t const refinement_factor = std::pow(2, refinements);
 
     auto const verbose = parset.get<bool>("verbose");
     Solver::VerbosityMode const verbosity =