diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 0eaf331091bbb30e7a07f204d34fc90ada1b7bfb..66f36b6efe66923fd8016da8e24ed803bc5466dd 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4379,7 +4379,7 @@ inline void gcode_M111() {
     uint8_t comma = 0;
     for (uint8_t i = 0; i < COUNT(debug_strings); i++) {
       if (TEST(marlin_debug_flags, i)) {
-        if (comma++) SERIAL_CHAR('|');
+        if (comma++) SERIAL_CHAR(',');
         serialprintPGM((char*)pgm_read_word(&(debug_strings[i])));
       }
     }
diff --git a/Marlin/language.h b/Marlin/language.h
index 5d8033e363501c8c68675a98757eae5a073471ca..264f679d0f5dc1787d176fc44ada2d81b479c45c 100644
--- a/Marlin/language.h
+++ b/Marlin/language.h
@@ -225,7 +225,7 @@
 #define MSG_T_MINTEMP                       "MINTEMP triggered"
 
 // Debug
-#define MSG_DEBUG_PREFIX                    "DEBUG: "
+#define MSG_DEBUG_PREFIX                    "DEBUG:"
 #define MSG_DEBUG_OFF                       "off"
 #define MSG_DEBUG_ECHO                      "ECHO"
 #define MSG_DEBUG_INFO                      "INFO"