diff --git a/loc_api/libloc_api_50001/loc_eng_nmea.cpp b/loc_api/libloc_api_50001/loc_eng_nmea.cpp
index e30380c9..9f087ca5 100644
--- a/loc_api/libloc_api_50001/loc_eng_nmea.cpp
+++ b/loc_api/libloc_api_50001/loc_eng_nmea.cpp
@@ -89,7 +89,7 @@ int loc_eng_nmea_put_checksum(char *pNmea, int maxSize)
         length++;
     }
 
-    int checksumLength = snprintf(pNmea, maxSize,"*%02X\r\n", checksum);
+    int checksumLength = snprintf(pNmea,(maxSize-length-1),"*%02X\r\n", checksum);
     return (length + checksumLength);
 }