diff --git a/include/spdlog/details/periodic_worker.h b/include/spdlog/details/periodic_worker.h
index ccac6ff2..d647b66e 100644
--- a/include/spdlog/details/periodic_worker.h
+++ b/include/spdlog/details/periodic_worker.h
@@ -38,7 +38,7 @@ public:
             }
         });
     }
-    std::thread *get_thread() { return &worker_thread_; }
+    std::thread &get_thread() { return worker_thread_; }
     periodic_worker(const periodic_worker &) = delete;
     periodic_worker &operator=(const periodic_worker &) = delete;
     // stop the worker thread and join it
diff --git a/include/spdlog/details/registry.h b/include/spdlog/details/registry.h
index feb6d4f3..1dff8cdb 100644
--- a/include/spdlog/details/registry.h
+++ b/include/spdlog/details/registry.h
@@ -68,7 +68,7 @@ public:
         periodic_flusher_ = details::make_unique<periodic_worker>(clbk, interval);
     }
 
-    std::unique_ptr<periodic_worker> &get_flusher() { return periodic_flusher_; }
+    std::unique_ptr<periodic_worker> &get_flusher() { std::lock_guard<std::mutex> lock(flusher_mutex_); return periodic_flusher_; }
 
     void set_error_handler(err_handler handler);
 
diff --git a/include/spdlog/spdlog-inl.h b/include/spdlog/spdlog-inl.h
index fac47986..97c36222 100644
--- a/include/spdlog/spdlog-inl.h
+++ b/include/spdlog/spdlog-inl.h
@@ -89,9 +89,4 @@ SPDLOG_INLINE void apply_logger_env_levels(std::shared_ptr<logger> logger) {
     details::registry::instance().apply_logger_env_levels(std::move(logger));
 }
 
-SPDLOG_INLINE std::unique_ptr<spdlog::details::periodic_worker> &get_flusher()
-{
-    return details::registry::instance().get_flusher();
-}
-
 }  // namespace spdlog