diff --git a/mainloop.hpp b/mainloop.hpp
index 6c5b8e0..b3de022 100644
--- a/mainloop.hpp
+++ b/mainloop.hpp
@@ -156,4 +156,4 @@
 /** @brief Given a value and map of interfaces, update values and check
  * thresholds.
  */
-void updateSensorInterfaces(InterfaceMap& ifaces, int64_t value);
+void updateSensorInterfaces(InterfaceMap& ifaces, SensorValueType value);