diff --git a/src/Mod/CAM/PathSimulator/AppGL/MillSimulation.cpp b/src/Mod/CAM/PathSimulator/AppGL/MillSimulation.cpp
index a59adb12aa..2a166343eb 100644
--- a/src/Mod/CAM/PathSimulator/AppGL/MillSimulation.cpp
+++ b/src/Mod/CAM/PathSimulator/AppGL/MillSimulation.cpp
@@ -79,6 +79,9 @@ void MillSimulation::SimNext()
 
     if (mCurStep < mNTotalSteps) {
         mCurStep += mSimSpeed;
+        if (mCurStep > mNTotalSteps) {
+            mCurStep = mNTotalSteps;
+        }
         CalcSegmentPositions();
         simDisplay.updateDisplay = true;
     }