diff --git a/Marlin/src/Marlin.cpp b/Marlin/src/Marlin.cpp
index 0b22e745bb..2d42dbaae0 100644
--- a/Marlin/src/Marlin.cpp
+++ b/Marlin/src/Marlin.cpp
@@ -84,6 +84,7 @@
 
 #if ENABLED(EXPERIMENTAL_I2CBUS)
   #include "feature/twibus.h"
+  TWIBus i2c;
 #endif
 
 #if ENABLED(I2C_POSITION_ENCODERS)
@@ -98,10 +99,6 @@
   CardReader card;
 #endif
 
-#if ENABLED(EXPERIMENTAL_I2CBUS)
-  TWIBus i2c;
-#endif
-
 #if ENABLED(G38_PROBE_TARGET)
   bool G38_move = false,
        G38_endstop_hit = false;
@@ -355,10 +352,6 @@ bool pin_is_protected(const int8_t pin) {
   return false;
 }
 
-#if ENABLED(EXPERIMENTAL_I2CBUS)
-  #include "gcode/feature/i2c/M260_M261.h"
-#endif
-
 #if HAS_SERVOS
   #include "gcode/control/M280.h"
 #endif
diff --git a/Marlin/src/Marlin.h b/Marlin/src/Marlin.h
index 84bb67ba97..ba37ccd598 100644
--- a/Marlin/src/Marlin.h
+++ b/Marlin/src/Marlin.h
@@ -143,6 +143,11 @@ void manage_inactivity(bool ignore_stepper_queue = false);
 
 #endif // !MIXING_EXTRUDER
 
+#if ENABLED(EXPERIMENTAL_I2CBUS)
+  #include "feature/twibus.h"
+  extern TWIBus i2c;
+#endif
+
 #if ENABLED(G38_PROBE_TARGET)
   extern bool G38_move,        // flag to tell the interrupt handler that a G38 command is being run
               G38_endstop_hit; // flag from the interrupt handler to indicate if the endstop went active
diff --git a/Marlin/src/gcode/feature/i2c/M260_M261.h b/Marlin/src/gcode/feature/i2c/M260_M261.cpp
similarity index 91%
rename from Marlin/src/gcode/feature/i2c/M260_M261.h
rename to Marlin/src/gcode/feature/i2c/M260_M261.cpp
index c66d19c52b..fdfa5804d6 100644
--- a/Marlin/src/gcode/feature/i2c/M260_M261.h
+++ b/Marlin/src/gcode/feature/i2c/M260_M261.cpp
@@ -20,6 +20,14 @@
  *
  */
 
+#include "../../../inc/MarlinConfig.h"
+
+#if ENABLED(EXPERIMENTAL_I2CBUS)
+
+#include "../../gcode.h"
+
+#include "../../../Marlin.h" // for i2c
+
 /**
  * M260: Send data to a I2C slave device
  *
@@ -36,7 +44,7 @@
  *  M260 R1 ; Reset the buffer without sending data
  *
  */
-void gcode_M260() {
+void GcodeSuite::M260() {
   // Set the target address
   if (parser.seen('A')) i2c.address(parser.value_byte());
 
@@ -55,7 +63,7 @@ void gcode_M260() {
  *
  * Usage: M261 A<slave device address base 10> B<number of bytes>
  */
-void gcode_M261() {
+void GcodeSuite::M261() {
   if (parser.seen('A')) i2c.address(parser.value_byte());
 
   uint8_t bytes = parser.byteval('B', 1);
@@ -68,3 +76,5 @@ void gcode_M261() {
     SERIAL_ERRORLN("Bad i2c request");
   }
 }
+
+#endif
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 79dd5e3bc7..7de00309e0 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -121,8 +121,6 @@ extern void gcode_M164();
 extern void gcode_M165();
 extern void gcode_M240();
 extern void gcode_M250();
-extern void gcode_M260();
-extern void gcode_M261();
 extern void gcode_M280();
 extern void gcode_M300();
 extern void gcode_M301();
@@ -602,16 +600,9 @@ void GcodeSuite::process_next_command() {
       #endif // HAS_LCD_CONTRAST
 
       #if ENABLED(EXPERIMENTAL_I2CBUS)
-
-        case 260: // M260: Send data to an i2c slave
-          gcode_M260();
-          break;
-
-        case 261: // M261: Request data from an i2c slave
-          gcode_M261();
-          break;
-
-      #endif // EXPERIMENTAL_I2CBUS
+        case 260: M260(); break;  // M260: Send data to an i2c slave
+        case 261: M261(); break;  // M261: Request data from an i2c slave
+      #endif
 
       #if ENABLED(PREVENT_COLD_EXTRUSION)
         case 302: // M302: Allow cold extrudes (set the minimum extrude temperature)