diff --git a/src/canvaslms/grades/tilkryLAB1.nw b/src/canvaslms/grades/tilkryLAB1.nw
index 21aea10..d3676fe 100644
--- a/src/canvaslms/grades/tilkryLAB1.nw
+++ b/src/canvaslms/grades/tilkryLAB1.nw
@@ -255,9 +255,14 @@ def is_optional(assignment):
 
 If the assignment is mandatory, we'll add the grade to [[mandatory]].
 If there is no grade or submission, we'll treat it as an F.
+
+We also added a grade P+, for the fun of it, on one assignment.
+We treat it as a normal P though.
 <<handle mandatory>>=
 if grade is None:
   grade = "F"
+elif grade == "P+":
+  grade = "P"
 elif grade not in "PF":
   logging.warning(f"Invalid grade {grade} for {user} in {assignment}, "
                   "using F")