ibid

Marlin/src/gcode/calibrate/G34_M422.cpp

@@ -25,6 +25,8 @@
 #if ENABLED(Z_STEPPER_AUTO_ALIGN)
 
 #include "../gcode.h"
+#include "../../feature/z_stepper_align.h"
+
 #include "../../module/planner.h"
 #include "../../module/stepper.h"
 #include "../../module/motion.h"
@@ -35,8 +37,8 @@
   #include "../../feature/bedlevel/bedlevel.h"
 #endif
 
-#if HAS_MULTI_HOTEND
-  #include "../../module/tool_change.h"
+#if ENABLED(Z_STEPPER_ALIGN_KNOWN_STEPPER_POSITIONS)
+   #include "../../libs/least_squares_fit.h"
 #endif
 
 #define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)