diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index e10d778d5..e8401ffa8 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4510,9 +4510,6 @@ inline void gcode_M303() {
   int c = code_seen('C') ? code_value_short() : 5;
   float temp = code_seen('S') ? code_value() : (e < 0 ? 70.0 : 150.0);
   PID_autotune(temp, e, c);
-  // Suppress a line mismatch error
-  gcode_LastN += 1;
-  FlushSerialRequestResend();
 }
 
 #ifdef SCARA
diff --git a/Marlin/language.h b/Marlin/language.h
index 588b568b4..c852693b6 100644
--- a/Marlin/language.h
+++ b/Marlin/language.h
@@ -195,8 +195,8 @@
 #define MSG_KP                              " Kp: "
 #define MSG_KI                              " Ki: "
 #define MSG_KD                              " Kd: "
-#define MSG_OK_B                            "ok B:"
-#define MSG_OK_T                            "ok T:"
+#define MSG_B                               "B:"
+#define MSG_T                               "T:"
 #define MSG_AT                              " @:"
 #define MSG_PID_AUTOTUNE_FINISHED           MSG_PID_AUTOTUNE " finished! Put the last Kp, Ki and Kd constants from below into Configuration.h"
 #define MSG_PID_DEBUG                       " PID_DEBUG "
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 16d3cfc61..edbab7f19 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -191,8 +191,7 @@ static void updateTemperaturesFromRawValues();
 //================================ Functions ================================
 //===========================================================================
 
-void PID_autotune(float temp, int extruder, int ncycles)
-{
+void PID_autotune(float temp, int extruder, int ncycles) {
   float input = 0.0;
   int cycles = 0;
   bool heating = true;
@@ -324,11 +323,11 @@ void PID_autotune(float temp, int extruder, int ncycles)
       int p;
       if (extruder < 0) {
         p = soft_pwm_bed;
-        SERIAL_PROTOCOLPGM(MSG_OK_B);
+        SERIAL_PROTOCOLPGM(MSG_B);
       }
       else {
         p = soft_pwm[extruder];
-        SERIAL_PROTOCOLPGM(MSG_OK_T);
+        SERIAL_PROTOCOLPGM(MSG_T);
       }
 
       SERIAL_PROTOCOL(input);