diff --git a/gcode_parse.c b/gcode_parse.c
index 9b51192..e3d059d 100644
--- a/gcode_parse.c
+++ b/gcode_parse.c
@@ -324,7 +324,8 @@ void gcode_parse_char(uint8_t c) {
 
 		if (
 		#ifdef	REQUIRE_LINENUMBER
-			(next_target.N >= next_target.N_expected) && (next_target.seen_N == 1)
+			((next_target.N >= next_target.N_expected) && (next_target.seen_N == 1)) ||
+			(next_target.seen_M && (next_target.M == 110))
 		#else
 			1
 		#endif
diff --git a/gcode_process.c b/gcode_process.c
index 3bb46ff..b963569 100644
--- a/gcode_process.c
+++ b/gcode_process.c
@@ -364,7 +364,7 @@ void process_gcode_command() {
 				
 			// M110- set line number
 			case 110:
-				next_target.N_expected = next_target.S - 1;
+				// this is a no-op in Teacup
 				break;
 			// M111- set debug level
 			#ifdef	DEBUG