diff --git a/inputs/precipitator_lowres.in b/inputs/precipitator_lowres.in
index 3acdb1de..0d82a203 100644
--- a/inputs/precipitator_lowres.in
+++ b/inputs/precipitator_lowres.in
@@ -108,7 +108,7 @@ perturb_exponent = 1    # P(k) ~ k^{-2}
 sigma_v = 0.0001   # kpc Myr^{-1}
 k_peak = 2
 num_modes = 12
-xy_modes_only = true
+vertical_driving_only = true
 sol_weight = 1.0
 rseed = 42
 t_corr = 500.0   # Myr
diff --git a/src/pgen/precipitator.cpp b/src/pgen/precipitator.cpp
index 4d8e5f36..2f248391 100644
--- a/src/pgen/precipitator.cpp
+++ b/src/pgen/precipitator.cpp
@@ -791,8 +791,8 @@ void ProblemInitPackageData(ParameterInput *pin, parthenon::StateDescriptor *pkg
 
     // when only v_z is desired, ensure that always k_z == 0
     const bool xy_modes_only = vertical_driving_only;
-    auto k_vec_v = utils::few_modes_ft::MakeRandomModes(num_modes_v, k_peak_v,
-                                                        xy_modes_only, rseed_v);
+    auto k_vec_v = utils::few_modes_ft::MakeRandomModes(num_modes_v, k_peak_v, rseed_v,
+                                                        vertical_driving_only);
 
     auto few_modes_ft = FewModesFT(pin, hydro_pkg, "precipitator_perturb_v", num_modes_v,
                                    k_vec_v, k_peak_v, sol_weight_v, t_corr, rseed_v);