diff --git a/measurement_main.py b/measurement_main.py
old mode 100755
new mode 100644
index 7f302a5..69e0bd0
--- a/measurement_main.py
+++ b/measurement_main.py
@@ -251,7 +251,7 @@ def monitor_gps(ser, output_file):
         while ser.is_open:
             nmea_sentence = ser.readline() #GPRMC
             nmea_str = nmea_sentence.decode("utf-8")
-            if nmea_str.startswith("$GPGGA"):
+            if nmea_str.startswith("$GPRMC"):
                 write_to_file(output_file, nmea_str)
     except:
         if not ser.is_open: