diff --git a/virtualSensor.hpp b/virtualSensor.hpp
index 01e3221..0667246 100644
--- a/virtualSensor.hpp
+++ b/virtualSensor.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "dbusSensor.hpp"
 #include "exprtkTools.hpp"
 #include "thresholds.hpp"
@@ -11,9 +13,7 @@
 #include <map>
 #include <string>
 
-namespace phosphor
-{
-namespace virtualSensor
+namespace phosphor::virtual_sensor
 {
 
 PHOSPHOR_LOG2_USING_WITH_FLAGS;
@@ -65,7 +65,8 @@
      * @param[in] path    - The Dbus path of sensor
      * @param[in] ctx     - sensor context for update
      */
-    SensorParam(sdbusplus::bus_t& bus, const std::string& path, void* ctx) :
+    SensorParam(sdbusplus::bus_t& bus, const std::string& path,
+                VirtualSensor& ctx) :
         dbusSensor(std::make_unique<DbusSensor>(bus, path, ctx)),
         paramType(dbusParam)
     {}
@@ -75,7 +76,9 @@
 
   private:
     std::unique_ptr<DbusSensor> dbusSensor = nullptr;
-    double value = 0;
+
+    /** @brief virtual sensor value */
+    double value = std::numeric_limits<double>::quiet_NaN();
     ParamType paramType;
 };
 
@@ -122,8 +125,10 @@
 
     /** @brief Set sensor value */
     void setSensorValue(double value);
+
     /** @brief Update sensor at regular intrval */
     void updateVirtualSensor();
+
     /** @brief Check if sensor value is in valid range */
     bool sensorInRange(double value);
 
@@ -300,5 +305,4 @@
     void setupMatches();
 };
 
-} // namespace virtualSensor
-} // namespace phosphor
+} // namespace phosphor::virtual_sensor