diff --git a/libraries/SondeLib/M10M20.cpp b/libraries/SondeLib/M10M20.cpp
index b6ddb40..afe1048 100644
--- a/libraries/SondeLib/M10M20.cpp
+++ b/libraries/SondeLib/M10M20.cpp
@@ -387,13 +387,13 @@ void M10M20::processM10data(uint8_t dt)
 				// 45 20 7x => M20
 				if(rxp==2 && dataptr[0]==0x45 && dataptr[1]==0x20) { isM20 = true; }
 				if(isM20) {
-					memcpy(sonde.si()->typestr, "M20", 4);
+					memcpy(sonde.si()->typestr, "M20 ", 5);
 					if(rxp>=M20_FRAMELEN) {
 						rxsearching = true;
 						haveNewFrame = decodeframeM20(dataptr);
 					}
 				} else {
-					memcpy(sonde.si()->typestr, "M10", 4);
+					memcpy(sonde.si()->typestr, "M10 ", 5);
 					if(rxp>=M10_FRAMELEN) {
 						rxsearching = true;
 						haveNewFrame = decodeframeM10(dataptr);