diff --git a/opensource/ReadRinexNav.m b/opensource/ReadRinexNav.m
index e6035e2..7a0d44a 100644
--- a/opensource/ReadRinexNav.m
+++ b/opensource/ReadRinexNav.m
@@ -22,7 +22,7 @@ function [gpsEph,iono] = ReadRinexNav(fileName)
 % gpsEph(i).Cus     % Sine harmonic correction to argument of latitude (radians)
 % gpsEph(i).Asqrt   % Square root of semi-major axis (meters^1/2)
 % gpsEph(i).Toe     % Reference time of ephemeris (seconds)
-% gpsEph(i).Cic     % Sine harmonic correction to angle of inclination (radians)
+% gpsEph(i).Cic     % Cosine harmonic correction to angle of inclination (radians)
 % gpsEph(i).OMEGA   % Longitude of ascending node at weekly epoch (radians)
 % gpsEph(i).Cis     % Sine harmonic correction to angle of inclination (radians)
 % gpsEph(i).i0      % Inclination angle at reference time (radians)