diff --git a/Marlin/src/Marlin.cpp b/Marlin/src/Marlin.cpp
index 38801990f6..10c223849a 100644
--- a/Marlin/src/Marlin.cpp
+++ b/Marlin/src/Marlin.cpp
@@ -353,14 +353,6 @@ float cartes[XYZ] = { 0 };
   int lpq_len = 20;
 #endif
 
-#if ENABLED(HOST_KEEPALIVE_FEATURE)
-  MarlinBusyState busy_state = NOT_BUSY;
-  static millis_t next_busy_signal_ms = 0;
-  uint8_t host_keepalive_interval = DEFAULT_KEEPALIVE_INTERVAL;
-#else
-  #define host_keepalive() NOOP
-#endif
-
 #if ENABLED(I2C_POSITION_ENCODERS)
   I2CPositionEncodersMgr I2CPEM;
   uint8_t blockBufferIndexRef = 0;
@@ -2245,46 +2237,6 @@ static void homeaxis(const AxisEnum axis) {
 
 #endif
 
-/**
- * ***************************************************************************
- * ***************************** G-CODE HANDLING *****************************
- * ***************************************************************************
- */
-
-#if ENABLED(HOST_KEEPALIVE_FEATURE)
-
-  /**
-   * Output a "busy" message at regular intervals
-   * while the machine is not accepting commands.
-   */
-  void host_keepalive() {
-    const millis_t ms = millis();
-    if (host_keepalive_interval && busy_state != NOT_BUSY) {
-      if (PENDING(ms, next_busy_signal_ms)) return;
-      switch (busy_state) {
-        case IN_HANDLER:
-        case IN_PROCESS:
-          SERIAL_ECHO_START();
-          SERIAL_ECHOLNPGM(MSG_BUSY_PROCESSING);
-          break;
-        case PAUSED_FOR_USER:
-          SERIAL_ECHO_START();
-          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_USER);
-          break;
-        case PAUSED_FOR_INPUT:
-          SERIAL_ECHO_START();
-          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_INPUT);
-          break;
-        default:
-          break;
-      }
-    }
-    next_busy_signal_ms = ms + host_keepalive_interval * 1000UL;
-  }
-
-#endif // HOST_KEEPALIVE_FEATURE
-
-
 /**************************************************
  ***************** GCode Handlers *****************
  **************************************************/
@@ -3574,7 +3526,9 @@ void idle(
 
   lcd_update();
 
-  host_keepalive();
+  #if ENABLED(HOST_KEEPALIVE_FEATURE)
+    gcode.host_keepalive();
+  #endif
 
   #if ENABLED(AUTO_REPORT_TEMPERATURES) && (HAS_TEMP_HOTEND || HAS_TEMP_BED)
     auto_report_temperatures();
diff --git a/Marlin/src/Marlin.h b/Marlin/src/Marlin.h
index f56dd4e1d7..527a030e12 100644
--- a/Marlin/src/Marlin.h
+++ b/Marlin/src/Marlin.h
@@ -266,13 +266,6 @@ extern float soft_endstop_min[XYZ], soft_endstop_max[XYZ];
   #define STOW_PROBE()
 #endif
 
-#if ENABLED(HOST_KEEPALIVE_FEATURE)
-  extern MarlinBusyState busy_state;
-  #define KEEPALIVE_STATE(n) do{ busy_state = n; }while(0)
-#else
-  #define KEEPALIVE_STATE(n) NOOP
-#endif
-
 #if FAN_COUNT > 0
   extern int16_t fanSpeeds[FAN_COUNT];
   #if ENABLED(PROBING_FANS_OFF)
diff --git a/Marlin/src/core/enum.h b/Marlin/src/core/enum.h
index 9bee5db459..9bf3ba856a 100644
--- a/Marlin/src/core/enum.h
+++ b/Marlin/src/core/enum.h
@@ -121,20 +121,6 @@ enum EndstopEnum {
   #endif
 #endif
 
-/**
- * States for managing Marlin and host communication
- * Marlin sends messages if blocked or busy
- */
-#if ENABLED(HOST_KEEPALIVE_FEATURE)
-  enum MarlinBusyState {
-    NOT_BUSY,           // Not in a handler
-    IN_HANDLER,         // Processing a GCode
-    IN_PROCESS,         // Known to be blocking command input (as in G29)
-    PAUSED_FOR_USER,    // Blocking pending any input
-    PAUSED_FOR_INPUT    // Blocking pending text input (concept)
-  };
-#endif
-
 /**
  * SD Card
  */
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 7fd4f0df3d..1b1525de84 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -41,6 +41,11 @@ millis_t GcodeSuite::previous_cmd_ms;
 
 bool GcodeSuite::axis_relative_modes[] = AXIS_RELATIVE_MODES;
 
+#if ENABLED(HOST_KEEPALIVE_FEATURE)
+  GcodeSuite::MarlinBusyState GcodeSuite::busy_state = NOT_BUSY;
+  uint8_t GcodeSuite::host_keepalive_interval = DEFAULT_KEEPALIVE_INTERVAL;
+#endif
+
 /**
  * Set target_extruder from the T parameter or the active_extruder
  *
@@ -1068,3 +1073,37 @@ void GcodeSuite::process_next_command() {
 
   ok_to_send();
 }
+
+#if ENABLED(HOST_KEEPALIVE_FEATURE)
+
+  /**
+   * Output a "busy" message at regular intervals
+   * while the machine is not accepting commands.
+   */
+  void GcodeSuite::host_keepalive() {
+    const millis_t ms = millis();
+    static millis_t next_busy_signal_ms = 0;
+    if (host_keepalive_interval && busy_state != NOT_BUSY) {
+      if (PENDING(ms, next_busy_signal_ms)) return;
+      switch (busy_state) {
+        case IN_HANDLER:
+        case IN_PROCESS:
+          SERIAL_ECHO_START();
+          SERIAL_ECHOLNPGM(MSG_BUSY_PROCESSING);
+          break;
+        case PAUSED_FOR_USER:
+          SERIAL_ECHO_START();
+          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_USER);
+          break;
+        case PAUSED_FOR_INPUT:
+          SERIAL_ECHO_START();
+          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_INPUT);
+          break;
+        default:
+          break;
+      }
+    }
+    next_busy_signal_ms = ms + host_keepalive_interval * 1000UL;
+  }
+
+#endif // HOST_KEEPALIVE_FEATURE
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index 2f40b775b9..1fdd440d8c 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -263,6 +263,8 @@ public:
   static void get_destination_from_command();
   static void process_next_command();
 
+  static FORCE_INLINE void home_all_axes() { G28(true); }
+
   /**
    * Multi-stepper support for M92, M201, M203
    */
@@ -274,7 +276,28 @@ public:
     #define TARGET_EXTRUDER 0
   #endif
 
-  static FORCE_INLINE void home_all_axes() { G28(true); }
+  #if ENABLED(HOST_KEEPALIVE_FEATURE)
+    /**
+     * States for managing Marlin and host communication
+     * Marlin sends messages if blocked or busy
+     */
+    enum MarlinBusyState {
+      NOT_BUSY,           // Not in a handler
+      IN_HANDLER,         // Processing a GCode
+      IN_PROCESS,         // Known to be blocking command input (as in G29)
+      PAUSED_FOR_USER,    // Blocking pending any input
+      PAUSED_FOR_INPUT    // Blocking pending text input (concept)
+    };
+
+    static MarlinBusyState busy_state;
+    static uint8_t host_keepalive_interval;
+
+    static void host_keepalive();
+
+    #define KEEPALIVE_STATE(n) gcode.busy_state = gcode.n
+  #else
+    #define KEEPALIVE_STATE(n) NOOP
+  #endif
 
 private:
 
diff --git a/Marlin/src/gcode/host/M113.h b/Marlin/src/gcode/host/M113.h
index e7310dfa4e..59b26c7daf 100644
--- a/Marlin/src/gcode/host/M113.h
+++ b/Marlin/src/gcode/host/M113.h
@@ -27,11 +27,11 @@
  */
 void gcode_M113() {
   if (parser.seenval('S')) {
-    host_keepalive_interval = parser.value_byte();
-    NOMORE(host_keepalive_interval, 60);
+    gcode.host_keepalive_interval = parser.value_byte();
+    NOMORE(gcode.host_keepalive_interval, 60);
   }
   else {
     SERIAL_ECHO_START();
-    SERIAL_ECHOLNPAIR("M113 S", (unsigned long)host_keepalive_interval);
+    SERIAL_ECHOLNPAIR("M113 S", (unsigned long)gcode.host_keepalive_interval);
   }
 }