diff --git a/Assets/Scripts/Game/BallSpawner.cs b/Assets/Scripts/Game/BallSpawner.cs
index a8d38cf..3732700 100644
--- a/Assets/Scripts/Game/BallSpawner.cs
+++ b/Assets/Scripts/Game/BallSpawner.cs
@@ -135,8 +135,11 @@ public class BallSpawner : MonoBehaviour
         // As an exception, glass balls will collide with other glass balls.
         foreach (var ball in balls)
         {
+            if (ball == null) continue;
+
             foreach (var otherBall in balls)
             {
+                if (otherBall == null) continue;
                 if (ball == otherBall) continue;
 
                 bool ballIsBasicOrFruit = ball.CompareTag("BasicBall") || ball.CompareTag("FruitBall");