diff --git a/Marlin/src/Marlin.cpp b/Marlin/src/Marlin.cpp
index 9db7d77c9..995c6bdd1 100644
--- a/Marlin/src/Marlin.cpp
+++ b/Marlin/src/Marlin.cpp
@@ -374,8 +374,6 @@ bool pin_is_protected(const int8_t pin) {
   return false;
 }
 
-#include "gcode/control/M111.h"
-
 #if ENABLED(HOST_KEEPALIVE_FEATURE)
   #include "gcode/host/M113.h"
 #endif
diff --git a/Marlin/src/gcode/control/M111.h b/Marlin/src/gcode/control/M111.cpp
similarity index 94%
rename from Marlin/src/gcode/control/M111.h
rename to Marlin/src/gcode/control/M111.cpp
index 748796da6..1850ed2db 100644
--- a/Marlin/src/gcode/control/M111.h
+++ b/Marlin/src/gcode/control/M111.cpp
@@ -20,10 +20,12 @@
  *
  */
 
+#include "../gcode.h"
+
 /**
  * M111: Set the debug level
  */
-void gcode_M111() {
+void GcodeSuite::M111() {
   if (parser.seen('S')) marlin_debug_flags = parser.byteval('S');
 
   const static char str_debug_1[] PROGMEM = MSG_DEBUG_ECHO,
@@ -50,7 +52,7 @@ void gcode_M111() {
     for (uint8_t i = 0; i < COUNT(debug_strings); i++) {
       if (TEST(marlin_debug_flags, i)) {
         if (comma++) SERIAL_CHAR(',');
-        serialprintPGM((char*)pgm_read_word(&debug_strings[i]));
+        serialprintPGM((char*)pgm_read_ptr(&debug_strings[i]));
       }
     }
   }
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 822c31786..f9f508ffd 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -124,7 +124,6 @@ extern void gcode_M83();
 extern void gcode_M85();
 extern void gcode_M92();
 extern void gcode_M100();
-extern void gcode_M111();
 extern void gcode_M113();
 extern void gcode_M114();
 extern void gcode_M115();
@@ -449,9 +448,7 @@ void GcodeSuite::process_next_command() {
 
       case 110: M110(); break;    // M110: Set Current Line Number
 
-      case 111: // M111: Set debug level
-        gcode_M111();
-        break;
+      case 111: M111(); break;    // M111: Set debug level
 
       #if DISABLED(EMERGENCY_PARSER)
         case 108: M108(); break;  // M108: Cancel Waiting