diff --git a/Content/Projectiles/Boss/DuneWyrm/Timekeeper.cs b/Content/Projectiles/Boss/DuneWyrm/Timekeeper.cs
index 74552fa..45567b4 100644
--- a/Content/Projectiles/Boss/DuneWyrm/Timekeeper.cs
+++ b/Content/Projectiles/Boss/DuneWyrm/Timekeeper.cs
@@ -22,7 +22,8 @@ namespace Decimation.Content.Projectiles.Boss.DuneWyrm
             set => projectile.localAI[1] = value;
         }
 
-        private Projectile SiblingProjectile => Main.projectile[Sibling];
+        private Projectile SiblingProjectile =>
+            Sibling >= 0 && Sibling < Main.projectile.Length ? Main.projectile[Sibling] : null;
 
         private int Counter
         {