diff --git a/core/misc/singleton/singleton_manager.cpp b/core/misc/singleton/singleton_manager.cpp
index 2441514..3dec94a 100644
--- a/core/misc/singleton/singleton_manager.cpp
+++ b/core/misc/singleton/singleton_manager.cpp
@@ -50,14 +50,14 @@ void singleton_manager::release() const {
     {
         singleton_release_guard release_guard(true);
         for (int32_t j = singletons_.size() - 1; j >= 0; --j) {
-            auto s = singletons_[j];
+            const auto s = singletons_[j];
             release_guard.release_singleton(s);
         }
     }
     {
         singleton_release_guard release_guard(false);
         for (int32_t j = singletons_.size() - 1; j >= 0; --j) {
-            auto s = singletons_[j];
+            const auto s = singletons_[j];
             release_guard.release_singleton(s);
         }
     }