diff --git a/missions/misc/01_cal_nostradamus/skip/en.txt b/missions/misc/01_cal_nostradamus/skip/en.txt
index 8f8cf2583..ffcdd7f7a 100644
--- a/missions/misc/01_cal_nostradamus/skip/en.txt
+++ b/missions/misc/01_cal_nostradamus/skip/en.txt
@@ -1,4 +1,4 @@
-This mission is optionnal. You can skip it and go to the next one with the
+This mission is optional. You can skip it and go to the next one with the
 command
 
   $ gsh skip