diff --git a/rslib/src/scheduler/answering/current.rs b/rslib/src/scheduler/answering/current.rs
index c40513a18..65eb87044 100644
--- a/rslib/src/scheduler/answering/current.rs
+++ b/rslib/src/scheduler/answering/current.rs
@@ -71,7 +71,7 @@ impl CardStateUpdater {
                     // Decrease reps by 1 to get correct seed for fuzz.
                     // If the fuzz calculation changes, this will break.
                     let last_ivl_with_fuzz = self.learning_ivl_with_fuzz(
-                        get_fuzz_seed_for_id_and_reps(self.card.id, self.card.reps - 1),
+                        get_fuzz_seed_for_id_and_reps(self.card.id, self.card.reps.wrapping_sub(1)),
                         last_ivl,
                     );
                     let last_answered_time = due as i64 - last_ivl_with_fuzz as i64;