diff --git a/examples/the-purple-night/src/main.rs b/examples/the-purple-night/src/main.rs
index 02013e28..462ad01c 100644
--- a/examples/the-purple-night/src/main.rs
+++ b/examples/the-purple-night/src/main.rs
@@ -375,7 +375,7 @@ impl SwordState {
         }
     }
     fn jump_attack_frame(self, timer: u16) -> u16 {
-        (self.jump_attack_duration() - timer) / 8
+        (self.jump_attack_duration().saturating_sub(timer)) / 8
     }
     fn hold_frame(self) -> u16 {
         7