diff --git a/mainloop.cpp b/mainloop.cpp
index 486a175..11f03a5 100644
--- a/mainloop.cpp
+++ b/mainloop.cpp
@@ -208,6 +208,7 @@
 MainLoop::MainLoop(
     sdbusplus::bus::bus&& bus,
     const std::string& path,
+    const std::string& devPath,
     const char* prefix,
     const char* root)
     : _bus(std::move(bus)),
@@ -215,6 +216,7 @@
       _shutdown(false),
       _hwmonRoot(),
       _instance(),
+      _devPath(devPath),
       _prefix(prefix),
       _root(root),
       state()
diff --git a/mainloop.hpp b/mainloop.hpp
index d4ef2c4..90f1efa 100644
--- a/mainloop.hpp
+++ b/mainloop.hpp
@@ -29,6 +29,7 @@
          *
          *  @param[in] bus - sdbusplus bus client connection.
          *  @param[in] path - hwmon sysfs instance to manage
+         *  @param[in] devPath - physical device sysfs path.
          *  @param[in] prefix - DBus busname prefix.
          *  @param[in] root - DBus sensors namespace root.
          *
@@ -41,6 +42,7 @@
         MainLoop(
             sdbusplus::bus::bus&& bus,
             const std::string& path,
+            const std::string& devPath,
             const char* prefix,
             const char* root);
 
@@ -67,6 +69,8 @@
         std::string _hwmonRoot;
         /** @brief hwmon sysfs instance. */
         std::string _instance;
+        /** @brief physical device sysfs path. */
+        std::string _devPath;
         /** @brief DBus busname prefix. */
         const char* _prefix;
         /** @brief DBus sensors namespace root. */
diff --git a/readd.cpp b/readd.cpp
index 95c6887..c7d0466 100644
--- a/readd.cpp
+++ b/readd.cpp
@@ -53,9 +53,17 @@
     // Finished getting options out, so cleanup the parser.
     options.reset();
 
+    // Determine the physical device sysfs path.
+    auto calloutPath = sysfs::findCalloutPath(path);
+    if (calloutPath.empty())
+    {
+        exit_with_error("Unable to determine callout path.", argv);
+    }
+
     MainLoop loop(
         sdbusplus::bus::new_default(),
         path,
+        calloutPath,
         BUSNAME_PREFIX,
         SENSOR_ROOT);
     loop.run();
diff --git a/test/test.cpp b/test/test.cpp
index 07aaef7..90a07c0 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -37,6 +37,7 @@
     MainLoop loop(
         sdbusplus::bus::new_default(),
         dir,
+        dir,
         "xyz.openbmc_project.Testing", "/testing");
 
     auto threadMain = [](auto loop)