diff --git a/src/main/java/net/minecraft/server/BlockPiston.java b/src/main/java/net/minecraft/server/BlockPiston.java
index 17ba1e6fa5..d08f4274ec 100644
--- a/src/main/java/net/minecraft/server/BlockPiston.java
+++ b/src/main/java/net/minecraft/server/BlockPiston.java
@@ -218,6 +218,7 @@ public class BlockPiston extends Block {
     }
 
     public static int d(int i) {
+        if ((i & 7) >= Facing.a.length) return 0; // CraftBukkit - check for AIOOB on piston data
         return i & 7;
     }