diff --git a/PID_v1.cpp b/PID_v1.cpp
index cb6637c..2d6a922 100644
--- a/PID_v1.cpp
+++ b/PID_v1.cpp
@@ -65,8 +65,8 @@ bool PID::Compute()
       /*Compute all the working error variables*/
       double input = *myInput;
       double error = *mySetpoint - input;
-      double dInput = (input - lastInput);
-      outputSum+= (ki * error);
+      double dInput = 1000*(input - lastInput)/timechange;
+      outputSum+= 1000*(ki * error)/timechange;
 
       /*Add Proportional on Measurement, if P_ON_M is specified*/
       if(!pOnE) outputSum-= kp * dInput;