diff --git a/royalnet/engineer/sentry.py b/royalnet/engineer/sentry.py
index 4f4a9349..5d4fa462 100644
--- a/royalnet/engineer/sentry.py
+++ b/royalnet/engineer/sentry.py
@@ -16,7 +16,7 @@ from . import discard
 
 if t.TYPE_CHECKING:
     from .dispenser import Dispenser
-    from .bullet import Projectile, Casing
+    from .bullet import Projectile
 
 log = logging.getLogger(__name__)