diff --git a/Preprocessing_tools/nc_add_globatt.m b/Preprocessing_tools/nc_add_globatt.m
index 2b2907e3b71aed62c9ad128cfb17f8ec73178e53..1b2447617544765a9dab321fa5785f9a745967ee 100644
--- a/Preprocessing_tools/nc_add_globatt.m
+++ b/Preprocessing_tools/nc_add_globatt.m
@@ -27,7 +27,7 @@ function nc_add_globatt(filename,Yorig,Mmin,Dmin,Hmin,Min_min,Smin,product)
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 if nargin < 8
-    product = 'unknow'
+    product = 'unknown'
 end
 %
 origin_date = datestr(datenum(Yorig,Mmin,Dmin,Hmin,Min_min,Smin),0);