diff --git a/include/TachSensor.hpp b/include/TachSensor.hpp
index 8dd1b88..75dcd06 100644
--- a/include/TachSensor.hpp
+++ b/include/TachSensor.hpp
@@ -69,7 +69,7 @@
                boost::asio::io_service& io, const std::string& fanName,
                std::vector<thresholds::Threshold>&& thresholds,
                const std::string& sensorConfiguration,
-               const std::pair<size_t, size_t>& limits,
+               const std::pair<double, double>& limits,
                const PowerState& powerState,
                const std::optional<std::string>& led);
     ~TachSensor() override;