diff --git a/perf/benchmark_netcdf_io.jl b/perf/benchmark_netcdf_io.jl
index 8b9cf22008..4950fb7619 100644
--- a/perf/benchmark_netcdf_io.jl
+++ b/perf/benchmark_netcdf_io.jl
@@ -104,7 +104,7 @@ for device in keys(timings)
     NCDatasets.defDim(nc, "x", NUM)
     NCDatasets.defDim(nc, "y", NUM)
     NCDatasets.defDim(nc, "z", NUM)
-    v = NCDatasets.defVar(nc, "rhoa", Float32, ("time", "x", "y", "z"))
+    v = NCDatasets.defVar(nc, "rhoa", Float64, ("time", "x", "y", "z"))
     outarray = Array(netcdf_writer.remappers["rhoa"]._interpolated_values)
     v[1, :, :, :] = outarray