diff --git a/intern/cycles/blender/sync.cpp b/intern/cycles/blender/sync.cpp
index ee008bc6dca..8defad43afd 100644
--- a/intern/cycles/blender/sync.cpp
+++ b/intern/cycles/blender/sync.cpp
@@ -349,8 +349,7 @@ void BlenderSync::sync_integrator(BL::ViewLayer &b_view_layer, bool background)
 
   bool use_light_tree = get_boolean(cscene, "use_light_tree");
   integrator->set_use_light_tree(use_light_tree);
-  integrator->set_light_sampling_threshold(
-      (use_light_tree) ? 0.0f : get_float(cscene, "light_sampling_threshold"));
+  integrator->set_light_sampling_threshold(get_float(cscene, "light_sampling_threshold"));
 
   if (integrator->use_light_tree_is_modified()) {
     scene->light_manager->tag_update(scene, LightManager::UPDATE_ALL);
diff --git a/intern/cycles/kernel/light/light.h b/intern/cycles/kernel/light/light.h
index fe1df22bd60..5221845a79b 100644
--- a/intern/cycles/kernel/light/light.h
+++ b/intern/cycles/kernel/light/light.h
@@ -113,13 +113,16 @@ ccl_device_noinline bool light_sample(KernelGlobals kg,
 {
   int prim;
   MeshLight mesh_light;
+#ifdef __LIGHT_TREE__
   if (kernel_data.integrator.use_light_tree) {
     ccl_global const KernelLightTreeEmitter *kemitter = &kernel_data_fetch(light_tree_emitters,
                                                                            emitter_index);
     prim = kemitter->prim;
     mesh_light = kemitter->mesh_light;
   }
-  else {
+  else
+#endif
+  {
     ccl_global const KernelLightDistribution *kdistribution = &kernel_data_fetch(
         light_distribution, emitter_index);
     prim = kdistribution->prim;
diff --git a/intern/cycles/scene/integrator.cpp b/intern/cycles/scene/integrator.cpp
index 7e5633733ae..8fdec524d66 100644
--- a/intern/cycles/scene/integrator.cpp
+++ b/intern/cycles/scene/integrator.cpp
@@ -255,8 +255,10 @@ void Integrator::device_update(Device *device, DeviceScene *dscene, Scene *scene
   kintegrator->scrambling_distance = scrambling_distance;
   kintegrator->sobol_index_mask = reverse_integer_bits(next_power_of_two(aa_samples - 1) - 1);
 
-  kintegrator->use_light_tree = scene->integrator->use_light_tree;
-  if (light_sampling_threshold > 0.0f) {
+  /* NOTE: The kintegrator->use_light_tree is assigned to the efficient value in the light manager,
+   * and the synchronization code is expected to tag the light manager for update when the
+   * `use_light_tree` is changed. */
+  if (light_sampling_threshold > 0.0f && !kintegrator->use_light_tree) {
     kintegrator->light_inv_rr_threshold = scene->film->get_exposure() / light_sampling_threshold;
   }
   else {