diff --git a/src/phoebus_driver.cpp b/src/phoebus_driver.cpp
index 926d6161..fc223813 100644
--- a/src/phoebus_driver.cpp
+++ b/src/phoebus_driver.cpp
@@ -732,18 +732,22 @@ TaskListStatus PhoebusDriver::RadiationPostStep() {
       auto pmb = blocks[ib].get();
       auto &tl = async_region[ib];
       auto &sc0 = pmb->meshblock_data.Get(stage_name[integrator->nstages]);
-      auto calc_tau = tl.AddTask(none, radiation::LightBulbCalcTau, sc0.get());
-      auto check_do_gain_local = tl.AddTask(calc_tau, radiation::CheckDoGain, sc0.get(),
-                                            &(pdo_gain_reducer->val));
-      auto start_gain_reducer =
-          (ib == 0
-               ? tl.AddTask(check_do_gain_local, &parthenon::AllReduce<bool>::StartReduce,
-                            pdo_gain_reducer, MPI_LOR)
-               : none);
-      auto finish_gain_reducer = tl.AddTask(
-          start_gain_reducer, &parthenon::AllReduce<bool>::CheckReduce, pdo_gain_reducer);
-      int reg_dep_id = 0;
-      async_region.AddRegionalDependencies(reg_dep_id++, ib, finish_gain_reducer);
+      auto finish_gain_reducer = none;
+      if (do_lightbulb) {
+        auto calc_tau = tl.AddTask(none, radiation::LightBulbCalcTau, sc0.get());
+        auto check_do_gain_local = tl.AddTask(calc_tau, radiation::CheckDoGain, sc0.get(),
+                                              &(pdo_gain_reducer->val));
+        auto start_gain_reducer =
+            (ib == 0 ? tl.AddTask(check_do_gain_local,
+                                  &parthenon::AllReduce<bool>::StartReduce,
+                                  pdo_gain_reducer, MPI_LOR)
+                     : none);
+        finish_gain_reducer =
+            tl.AddTask(start_gain_reducer, &parthenon::AllReduce<bool>::CheckReduce,
+                       pdo_gain_reducer);
+        int reg_dep_id = 0;
+        async_region.AddRegionalDependencies(reg_dep_id++, ib, finish_gain_reducer);
+      }
 
       auto calculate_four_force =
           tl.AddTask(finish_gain_reducer, radiation::CoolingFunctionCalculateFourForce,
diff --git a/src/radiation/cooling_function.cpp b/src/radiation/cooling_function.cpp
index 7e33b556..642618e8 100644
--- a/src/radiation/cooling_function.cpp
+++ b/src/radiation/cooling_function.cpp
@@ -303,7 +303,7 @@ TaskStatus CoolingFunctionCalculateFourForce(MeshBlockData<Real> *rc, const doub
               for (int mu = Gcov_lo; mu <= Gcov_lo + 3; mu++) {
                 Kokkos::atomic_add(&(v(mu, k, j, i)), -detG * Gcov_coord[mu - Gcov_lo]);
               }
-              Kokkos::atomic_add(&(v(Gye, k, j, i)), LeptonSign(s) * detG * Jye);
+              Kokkos::atomic_add(&(v(Gye, k, j, i)), -LeptonSign(s) * detG * Jye);
             });
       }
     }