diff --git a/src/course/en/course.json b/src/course/en/course.json
index 3dc3d775e..2fa391e3d 100755
--- a/src/course/en/course.json
+++ b/src/course/en/course.json
@@ -62,7 +62,9 @@
         "incorrect": "Incorrect",
         "correct": "Correct",
         "locked": "Locked",
-        "visited": "Visited"
+        "visited": "Visited",
+        "required": "Required",
+        "optional": "Optional"
       }
     },
     "_extensions": {