diff --git a/include/vkd3d_shader.h b/include/vkd3d_shader.h
index 08e0b743..f775bf4c 100644
--- a/include/vkd3d_shader.h
+++ b/include/vkd3d_shader.h
@@ -251,6 +251,7 @@ struct vkd3d_shader_interface_local_info
     unsigned int shader_record_buffer_count;
     const struct vkd3d_shader_resource_binding *bindings;
     unsigned int binding_count;
+    uint32_t descriptor_size;
 };
 
 struct vkd3d_shader_transform_feedback_element
diff --git a/libs/vkd3d-shader/dxil.c b/libs/vkd3d-shader/dxil.c
index e588dda8..d83f8f3b 100644
--- a/libs/vkd3d-shader/dxil.c
+++ b/libs/vkd3d-shader/dxil.c
@@ -984,6 +984,19 @@ int vkd3d_shader_compile_dxil_export(const struct vkd3d_shader_code *dxil,
         }
     }
 
+    {
+        const struct dxil_spv_option_sbt_descriptor_size_log2 helper =
+                { { DXIL_SPV_OPTION_SBT_DESCRIPTOR_SIZE_LOG2 },
+                    vkd3d_bitmask_tzcnt32(shader_interface_local_info->descriptor_size),
+                    vkd3d_bitmask_tzcnt32(shader_interface_local_info->descriptor_size) };
+        if (dxil_spv_converter_add_option(converter, &helper.base) != DXIL_SPV_SUCCESS)
+        {
+            ERR("dxil-spirv does not support SBT_DESCRIPTOR_SIZE_LOG2.\n");
+            ret = VKD3D_ERROR_NOT_IMPLEMENTED;
+            goto end;
+        }
+    }
+
     {
         const struct dxil_spv_option_bindless_offset_buffer_layout helper =
                 { { DXIL_SPV_OPTION_BINDLESS_OFFSET_BUFFER_LAYOUT },
diff --git a/libs/vkd3d/raytracing_pipeline.c b/libs/vkd3d/raytracing_pipeline.c
index 066f13f1..418e7abb 100644
--- a/libs/vkd3d/raytracing_pipeline.c
+++ b/libs/vkd3d/raytracing_pipeline.c
@@ -576,6 +576,8 @@ static HRESULT d3d12_state_object_compile_pipeline(struct d3d12_state_object *ob
     else
         memset(&shader_interface_local_info, 0, sizeof(shader_interface_local_info));
 
+    shader_interface_local_info.descriptor_size = sizeof(struct d3d12_desc);
+
     for (i = 0; i < data->entry_points_count; i++)
     {
         entry = &data->entry_points[i];