diff --git a/Firmware/mmu2.cpp b/Firmware/mmu2.cpp
index ad6a28ba1..7e604f738 100644
--- a/Firmware/mmu2.cpp
+++ b/Firmware/mmu2.cpp
@@ -245,7 +245,17 @@ bool MMU2::VerifyFilamentEnteredPTFE() {
     // If the filament sensor reads 0 at any moment, then report FAILURE
 
     const float delta_mm = MMU2_CHECK_FILAMENT_PRESENCE_EXTRUSION_LENGTH - logic.ExtraLoadDistance();
-    const float length_step_mm = 2 * (delta_mm) / (LCD_WIDTH + 1);
+
+    // Allow some error in each pixel step. It is better to render too many pixels
+    // rather than too few. Note that 0.25mm is not enough but 0.50mm seems to work
+    // 0.50mm gives 1 digit precision
+    static constexpr float float_precision = 0.50; // mm
+
+    // The total length is twice delta_mm. Divide that length by number of pixels
+    // available to get length per pixel.
+    // Finally subtract the step length by the precision set above to allow some
+    // error introduced by CPU execution delays
+    const float length_step_mm = ( (2 * delta_mm) / LCD_WIDTH) - float_precision;
     float last_position = stepper_get_machine_position_E_mm();
 
     TryLoadUnloadProgressbarInit();
@@ -274,8 +284,10 @@ bool MMU2::VerifyFilamentEnteredPTFE() {
         fsensorStateLCD |= (WhereIsFilament() == FilamentState::NOT_PRESENT);
         fsensorState |= fsensorStateLCD; // No need to do the above comparison twice, just bitwise OR
 
-        if ((fabs(stepper_get_machine_position_E_mm() - last_position)) > length_step_mm) {
-            last_position = stepper_get_machine_position_E_mm(); // Reset
+        // Fetch the position once, to ensure last_position will be correct
+        float current_mm = stepper_get_machine_position_E_mm();
+        if (fabs(current_mm - last_position) > length_step_mm) {
+            last_position = current_mm;
             if (pixel > (LCD_WIDTH - 1)) pixel = LCD_WIDTH - 1;
             TryLoadUnloadProgressbar(pixel++, fsensorStateLCD);
             fsensorStateLCD = 0;      // Clear temporary bit