diff --git a/src/ecoprimer.c b/src/ecoprimer.c
index 4f1724d..deb6127 100644
--- a/src/ecoprimer.c
+++ b/src/ecoprimer.c
@@ -57,6 +57,7 @@ static void PrintHelp()
               PP      "-l    : minimum [L]ength : define the minimum amplication length. \n\n");
               PP      "-L    : maximum [L]ength : define the maximum amplicationlength. \n\n");
               PP      "-r    : [R]estricts the search to the given taxonomic id (restrict the example taxon set).\n\n");
+              PP      "-E    : [E]xception taxid allows to indicate than some subclade of example sequences are conterexamples.\n\n");
               PP      "-c    : Consider that the database sequences are [c]ircular\n\n");
               PP      "-3 	 : Three prime strict match\n\n");
               PP      "-q    : Strict matching [q]uorum, percentage of the sequences in which strict primers are found. By default it is 70\n\n");