diff --git a/src/model.cpp b/src/model.cpp
index 4dbfd93..ffd7069 100644
--- a/src/model.cpp
+++ b/src/model.cpp
@@ -858,6 +858,7 @@ bool Model::save(ModelData * model_data, bool save_whole_tree)
 void Model::save_tree(bool save_whole_tree)
 {
 	model_env->has_primary_key_set = has_primary_key_set;
+	SaveMode origin_save_mode = save_mode;
 
 	if( model_env->status && save_whole_tree )
 	{
@@ -897,7 +898,7 @@ void Model::save_tree(bool save_whole_tree)
 
 	if( model_env->status && save_whole_tree )
 	{
-		if( save_mode == DO_DELETE_ON_SAVE )
+		if( origin_save_mode == DO_DELETE_ON_SAVE )
 			model_env->model_work_mode = MORM_MODEL_WORK_MODE_ITERATE_THROUGH_CHILDS_WITH_FOREIGN_KEY;
 		else
 			model_env->model_work_mode = MORM_MODEL_WORK_MODE_ITERATE_THROUGH_CHILDS_WITHOUT_FOREIGN_KEY;