diff --git a/log_manager.hpp b/log_manager.hpp
index 9339a6f..d62a25e 100644
--- a/log_manager.hpp
+++ b/log_manager.hpp
@@ -130,6 +130,12 @@
                              const std::vector<std::string>& additionalData,
                              AssociationList& objects) const;
 
+        /** @brief Synchronize unwritten journal messages to disk.
+         *  @details This is the same implementation as the systemd command
+         *  "journalctl --sync".
+         */
+        void journalSync();
+
         /** @brief Persistent sdbusplus DBus bus connection. */
         sdbusplus::bus::bus& busLog;