diff --git a/nvme_manager.hpp b/nvme_manager.hpp
index 0ee23df..ffdb20a 100644
--- a/nvme_manager.hpp
+++ b/nvme_manager.hpp
@@ -155,6 +155,9 @@
     void read();
 
     std::vector<phosphor::nvme::Nvme::NVMeConfig> getNvmeConfig();
+
+    /** @brief Monitor interval in second  */
+    size_t monitorIntervalSec;
 };
 } // namespace nvme
 } // namespace phosphor