diff --git a/power-supply/power_supply.hpp b/power-supply/power_supply.hpp
index 5eb96a9..e88e257 100644
--- a/power-supply/power_supply.hpp
+++ b/power-supply/power_supply.hpp
@@ -389,6 +389,20 @@
         void updateInventory();
 
         /**
+         * @brief Toggles the GPIO to sync power supply input history readings
+         *
+         * This GPIO is connected to all supplies.  This will clear the
+         * previous readings out of the supplies and restart them both at the
+         * same time zero and at record ID 0.  The supplies will return 0
+         * bytes of data for the input history command right after this until
+         * a new entry shows up.
+         *
+         * This will cause the code to delete all previous history data and
+         * start fresh.
+         */
+        void syncHistory();
+
+        /**
          * @brief Reads the most recent input history record from the power
          *        supply and updates the average and maximum properties in
          *        D-Bus if there is a new reading available.