diff --git a/pid/fancontroller.hpp b/pid/fancontroller.hpp
index 821c900..f3d3f4e 100644
--- a/pid/fancontroller.hpp
+++ b/pid/fancontroller.hpp
@@ -28,9 +28,9 @@
     {
     }
 
-    float inputProc(void) override;
-    float setptProc(void) override;
-    void outputProc(float value) override;
+    double inputProc(void) override;
+    double setptProc(void) override;
+    void outputProc(double value) override;
 
     FanSpeedDirection getFanDirection(void) const
     {