diff --git a/Marlin/src/gcode/calibrate/M666.cpp b/Marlin/src/gcode/calibrate/M666.cpp
index 6a87e2944b..a8edb793ea 100644
--- a/Marlin/src/gcode/calibrate/M666.cpp
+++ b/Marlin/src/gcode/calibrate/M666.cpp
@@ -22,7 +22,7 @@
 
 #include "../../inc/MarlinConfig.h"
 
-#if ENABLED(DELTA) || ENABLED(Z_DUAL_ENDSTOPS)
+#if ENABLED(DELTA) || ENABLED(X_DUAL_ENDSTOPS) || ENABLED(Y_DUAL_ENDSTOPS) || ENABLED(Z_DUAL_ENDSTOPS)
 
 #include "../gcode.h"
 
@@ -67,7 +67,7 @@
    * M666: Set Dual Endstops offsets for X, Y, and/or Z.
    *       With no parameters report current offsets.
    */
-  inline void gcode_M666() {
+  inline void GcodeSuite::M666() {
     bool report = true;
     #if ENABLED(X_DUAL_ENDSTOPS)
       if (parser.seen('X')) {
@@ -104,4 +104,4 @@
 
 #endif // X_DUAL_ENDSTOPS || Y_DUAL_ENDSTOPS || Z_DUAL_ENDSTOPS
 
-#endif // DELTA || Z_DUAL_ENDSTOPS
+#endif // DELTA || X_DUAL_ENDSTOPS || Y_DUAL_ENDSTOPS || Z_DUAL_ENDSTOPS
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 938488996e..bb56eaf91e 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -488,7 +488,7 @@ void GcodeSuite::process_parsed_command() {
         case 665: M665(); break;  // M665: Set delta configurations
       #endif
 
-      #if ENABLED(DELTA) || ENABLED(Z_DUAL_ENDSTOPS)
+      #if ENABLED(DELTA) || ENABLED(X_DUAL_ENDSTOPS) || ENABLED(Y_DUAL_ENDSTOPS) || ENABLED(Z_DUAL_ENDSTOPS)
         case 666: M666(); break;  // M666: Set delta or dual endstop adjustment
       #endif
 
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index e04cc73f48..e618dcf05a 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -701,7 +701,7 @@ private:
     static void M665();
   #endif
 
-  #if ENABLED(DELTA) || ENABLED(Z_DUAL_ENDSTOPS)
+  #if ENABLED(DELTA) || ENABLED(X_DUAL_ENDSTOPS) || ENABLED(Y_DUAL_ENDSTOPS) || ENABLED(Z_DUAL_ENDSTOPS)
     static void M666();
   #endif