diff --git a/Marlin/src/Marlin.cpp b/Marlin/src/Marlin.cpp
index cef241e538..9d2772f50e 100644
--- a/Marlin/src/Marlin.cpp
+++ b/Marlin/src/Marlin.cpp
@@ -355,10 +355,6 @@ bool pin_is_protected(const int8_t pin) {
   return false;
 }
 
-#include "gcode/config/M203.h"
-#include "gcode/config/M204.h"
-#include "gcode/config/M205.h"
-
 #if HAS_M206_COMMAND
   #include "gcode/geometry/M206.h"
 #endif
diff --git a/Marlin/src/gcode/config/M203.h b/Marlin/src/gcode/config/M203.cpp
similarity index 93%
rename from Marlin/src/gcode/config/M203.h
rename to Marlin/src/gcode/config/M203.cpp
index bde9b7a861..60f9ce37be 100644
--- a/Marlin/src/gcode/config/M203.h
+++ b/Marlin/src/gcode/config/M203.cpp
@@ -20,12 +20,15 @@
  *
  */
 
+#include "../gcode.h"
+#include "../../module/planner.h"
+
 /**
  * M203: Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in units/sec
  *
  *       With multiple extruders use T to specify which one.
  */
-void gcode_M203() {
+void GcodeSuite::M203() {
 
   GET_TARGET_EXTRUDER();
 
diff --git a/Marlin/src/gcode/config/M204.h b/Marlin/src/gcode/config/M204.cpp
similarity index 95%
rename from Marlin/src/gcode/config/M204.h
rename to Marlin/src/gcode/config/M204.cpp
index 22d88f1d64..c8edcbf971 100644
--- a/Marlin/src/gcode/config/M204.h
+++ b/Marlin/src/gcode/config/M204.cpp
@@ -20,6 +20,9 @@
  *
  */
 
+#include "../gcode.h"
+#include "../../module/planner.h"
+
 /**
  * M204: Set Accelerations in units/sec^2 (M204 P1200 R3000 T3000)
  *
@@ -29,7 +32,7 @@
  *
  *  Also sets minimum segment time in ms (B20000) to prevent buffer under-runs and M20 minimum feedrate
  */
-void gcode_M204() {
+void GcodeSuite::M204() {
   if (parser.seen('S')) {  // Kept for legacy compatibility. Should NOT BE USED for new developments.
     planner.travel_acceleration = planner.acceleration = parser.value_linear_units();
     SERIAL_ECHOLNPAIR("Setting Print and Travel Acceleration: ", planner.acceleration);
diff --git a/Marlin/src/gcode/config/M205.h b/Marlin/src/gcode/config/M205.cpp
similarity index 95%
rename from Marlin/src/gcode/config/M205.h
rename to Marlin/src/gcode/config/M205.cpp
index 5b0ce3b578..e6b39150d0 100644
--- a/Marlin/src/gcode/config/M205.h
+++ b/Marlin/src/gcode/config/M205.cpp
@@ -20,6 +20,9 @@
  *
  */
 
+#include "../gcode.h"
+#include "../../module/planner.h"
+
 /**
  * M205: Set Advanced Settings
  *
@@ -31,7 +34,7 @@
  *    Z = Max Z Jerk (units/sec^2)
  *    E = Max E Jerk (units/sec^2)
  */
-void gcode_M205() {
+void GcodeSuite::M205() {
   if (parser.seen('S')) planner.min_feedrate_mm_s = parser.value_linear_units();
   if (parser.seen('T')) planner.min_travel_feedrate_mm_s = parser.value_linear_units();
   if (parser.seen('B')) planner.min_segment_time = parser.value_millis();
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 0ae62b6461..1525ba2fa5 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -119,9 +119,6 @@ void GcodeSuite::dwell(millis_t time) {
 extern void gcode_M163();
 extern void gcode_M164();
 extern void gcode_M165();
-extern void gcode_M203();
-extern void gcode_M204();
-extern void gcode_M205();
 extern void gcode_M206();
 extern void gcode_M211();
 extern void gcode_M220();
@@ -536,15 +533,9 @@ void GcodeSuite::process_next_command() {
         case 202: M202(); break; // Not used for Sprinter/grbl gen6
       #endif
 
-      case 203: // M203: Set max feedrate (units/sec)
-        gcode_M203();
-        break;
-      case 204: // M204: Set acceleration
-        gcode_M204();
-        break;
-      case 205: // M205: Set advanced settings
-        gcode_M205();
-        break;
+      case 203: M203(); break;    // M203: Set max feedrate (units/sec)
+      case 204: M204(); break;    // M204: Set acceleration
+      case 205: M205(); break;    // M205: Set advanced settings
 
       #if HAS_M206_COMMAND
         case 206: // M206: Set home offsets