diff --git a/Marlin/src/core/language.h b/Marlin/src/core/language.h
index fbd19bc0cc7b961d5108757c7db47ddbe67a1c78..7663eabb0ccbb6d4575f6e8b42f65bf14381bf42 100644
--- a/Marlin/src/core/language.h
+++ b/Marlin/src/core/language.h
@@ -197,7 +197,6 @@
 #define MSG_SKEW_MIN                        "min_skew_factor: "
 #define MSG_SKEW_MAX                        "max_skew_factor: "
 #define MSG_ERR_MATERIAL_INDEX              "M145 S<index> out of range (0-1)"
-#define MSG_ERR_M355_NONE                   "No case light"
 #define MSG_ERR_M421_PARAMETERS             "M421 incorrect parameter usage"
 #define MSG_ERR_BAD_PLANE_MODE              "G5 requires XY plane mode"
 #define MSG_ERR_MESH_XY                     "Mesh point cannot be resolved"
diff --git a/Marlin/src/gcode/feature/caselight/M355.cpp b/Marlin/src/gcode/feature/caselight/M355.cpp
index 3ad14791e5c5f12bf6e5a40eb622c14fe6ec4588..63443f4ff1e9ad4d5333d7240547912c9a990517 100644
--- a/Marlin/src/gcode/feature/caselight/M355.cpp
+++ b/Marlin/src/gcode/feature/caselight/M355.cpp
@@ -26,22 +26,20 @@
 
 #if HAS_CASE_LIGHT
   #include "../../../feature/caselight.h"
-#endif
 
-/**
- * M355: Turn case light on/off and set brightness
- *
- *   P<byte>  Set case light brightness (PWM pin required - ignored otherwise)
- *
- *   S<bool>  Set case light on/off
- *
- *   When S turns on the light on a PWM pin then the current brightness level is used/restored
- *
- *   M355 P200 S0 turns off the light & sets the brightness level
- *   M355 S1 turns on the light with a brightness of 200 (assuming a PWM pin)
- */
-void GcodeSuite::M355() {
-  #if HAS_CASE_LIGHT
+  /**
+   * M355: Turn case light on/off and set brightness
+   *
+   *   P<byte>  Set case light brightness (PWM pin required - ignored otherwise)
+   *
+   *   S<bool>  Set case light on/off
+   *
+   *   When S turns on the light on a PWM pin then the current brightness level is used/restored
+   *
+   *   M355 P200 S0 turns off the light & sets the brightness level
+   *   M355 S1 turns on the light with a brightness of 200 (assuming a PWM pin)
+   */
+  void GcodeSuite::M355() {
     uint8_t args = 0;
     if (parser.seenval('P')) {
       ++args, case_light_brightness = parser.value_byte();
@@ -62,7 +60,5 @@ void GcodeSuite::M355() {
       if (!USEABLE_HARDWARE_PWM(CASE_LIGHT_PIN)) SERIAL_ECHOLNPGM("Case light: on");
       else SERIAL_ECHOLNPAIR("Case light: ", case_light_brightness);
     }
-  #else
-    SERIAL_ERROR_MSG(MSG_ERR_M355_NONE);
-  #endif
-}
+  }
+#endif // HAS_CASE_LIGHT
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 9833f2d12a16db9a564715c56ff571fa127f17f5..4d4d9b77d71062a5f3a937615d75e86ab0d26542 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -669,7 +669,9 @@ void GcodeSuite::process_parsed_command(
         case 351: M351(); break;                                  // M351: Toggle MS1 MS2 pins directly, S# determines MS1 or MS2, X# sets the pin high/low.
       #endif
 
-      case 355: M355(); break;                                    // M355: Set case light brightness
+      #if HAS_CASE_LIGHT
+        case 355: M355(); break;                                  // M355: Set case light brightness
+      #endif
 
       #if ENABLED(DEBUG_GCODE_PARSER)
         case 800: parser.debug(); break;                          // M800: GCode Parser Test for M
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index bce726f2667158b22cfd3dca39db3f51917fb105..40d8785d8c2055c5dd6a71a883b6568eeb5f5f6c 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -672,7 +672,9 @@ private:
     static void M351();
   #endif
 
-  static void M355();
+  #if HAS_CASE_LIGHT
+    static void M355();
+  #endif
 
   #if ENABLED(MORGAN_SCARA)
     static bool M360();