diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index bdb65a4a7..0124d7b04 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -65,9 +65,8 @@ int8_t GcodeSuite::get_target_extruder_from_command() {
     const int8_t e = parser.value_byte();
     if (e >= EXTRUDERS) {
       SERIAL_ECHO_START();
-      SERIAL_CHAR('M');
-      SERIAL_ECHO(parser.codenum);
-      SERIAL_ECHOLNPAIR(" " MSG_INVALID_EXTRUDER " ", e);
+      SERIAL_CHAR('M'); SERIAL_ECHO(parser.codenum);
+      SERIAL_ECHOLNPAIR(" " MSG_INVALID_EXTRUDER " ", int(e));
       return -1;
     }
     return e;
diff --git a/Marlin/src/module/tool_change.cpp b/Marlin/src/module/tool_change.cpp
index b716c0192..da0d6afbf 100644
--- a/Marlin/src/module/tool_change.cpp
+++ b/Marlin/src/module/tool_change.cpp
@@ -417,10 +417,8 @@
 
 inline void invalid_extruder_error(const uint8_t e) {
   SERIAL_ECHO_START();
-  SERIAL_CHAR('T');
-  SERIAL_ECHO_F(e, DEC);
-  SERIAL_CHAR(' ');
-  SERIAL_ECHOLNPGM(MSG_INVALID_EXTRUDER);
+  SERIAL_CHAR('T'); SERIAL_ECHO(int(e));
+  SERIAL_CHAR(' '); SERIAL_ECHOLNPGM(MSG_INVALID_EXTRUDER);
 }
 
 #if ENABLED(DUAL_X_CARRIAGE)