diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index c78f517971f0522cbb8cead1e51672fc168e4ae9..74599ccae213fc75ad1665d30f099b393fe0d252 100755
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -330,7 +330,7 @@ bool axis_homed[XYZ] = { false }, axis_known_position[XYZ] = { false };
 /**
  * GCode line number handling. Hosts may opt to include line numbers when
  * sending commands to Marlin, and lines will be checked for sequentiality.
- * M110 S<int> sets the current line number.
+ * M110 N<int> sets the current line number.
  */
 static long gcode_N, gcode_LastN, Stopped_gcode_LastN = 0;
 
@@ -629,7 +629,7 @@ static bool send_ok[BUFSIZE];
 
 #ifdef CHDK
   millis_t chdkHigh = 0;
-  boolean chdkActive = false;
+  bool chdkActive = false;
 #endif
 
 #if ENABLED(PID_EXTRUSION_SCALING)
@@ -966,7 +966,7 @@ void gcode_line_error(const char* err, bool doFlush = true) {
 
 inline void get_serial_commands() {
   static char serial_line_buffer[MAX_CMD_SIZE];
-  static boolean serial_comment_mode = false;
+  static bool serial_comment_mode = false;
 
   // If the command buffer is empty for too long,
   // send "wait" to indicate Marlin is still waiting.
@@ -1006,7 +1006,7 @@ inline void get_serial_commands() {
 
       if (npos) {
 
-        boolean M110 = strstr_P(command, PSTR("M110")) != NULL;
+        bool M110 = strstr_P(command, PSTR("M110")) != NULL;
 
         if (M110) {
           char* n2pos = strchr(command + 4, 'N');
@@ -5680,7 +5680,7 @@ inline void gcode_M109() {
  * M110: Set Current Line Number
  */
 inline void gcode_M110() {
-  if (code_seen('N')) gcode_N = code_value_long();
+  if (code_seen('N')) gcode_LastN = code_value_long();
 }
 
 /**
diff --git a/Marlin/cardreader.cpp b/Marlin/cardreader.cpp
index e79200c2cb7199d9b141f68f90ebd74ec78bde2e..c8e94143c51a145126b958886fc2157d7f2e7f92 100644
--- a/Marlin/cardreader.cpp
+++ b/Marlin/cardreader.cpp
@@ -81,7 +81,7 @@ void CardReader::lsDive(const char *prepend, SdFile parent, const char * const m
       createFilename(lfilename, p);
 
       // Allocate enough stack space for the full path to a folder, trailing slash, and nul
-      boolean prepend_is_empty = (prepend[0] == '\0');
+      bool prepend_is_empty = (prepend[0] == '\0');
       int len = (prepend_is_empty ? 1 : strlen(prepend)) + strlen(lfilename) + 1 + 1;
       char path[len];
 
diff --git a/Marlin/servo.cpp b/Marlin/servo.cpp
index b5f9ed86daf50bf61bb44e099813c53ec5c48800..34f6dbde877be759700f6cd472b9906a0c7f2b39 100644
--- a/Marlin/servo.cpp
+++ b/Marlin/servo.cpp
@@ -227,7 +227,7 @@ static void finISR(timer16_Sequence_t timer) {
   #endif
 }
 
-static boolean isTimerActive(timer16_Sequence_t timer) {
+static bool isTimerActive(timer16_Sequence_t timer) {
   // returns true if any servo is active on this timer
   for (uint8_t channel = 0; channel < SERVOS_PER_TIMER; channel++) {
     if (SERVO(timer, channel).Pin.isActive)