diff --git a/src/main/java/net/minecraft/server/BlockBloodStone.java b/src/main/java/net/minecraft/server/BlockBloodStone.java
index 9a3c9efcc1..08aa0d62fa 100644
--- a/src/main/java/net/minecraft/server/BlockBloodStone.java
+++ b/src/main/java/net/minecraft/server/BlockBloodStone.java
@@ -12,7 +12,7 @@ public class BlockBloodStone extends Block {
 
     // Craftbukkit start
     public void a(World world, int i, int j, int k, int l) {
-        if (net.minecraft.server.Block.byId[l].c()) {
+        if (net.minecraft.server.Block.byId[l] != null && net.minecraft.server.Block.byId[l].c()) {
             CraftWorld craftWorld = ((WorldServer) world).getWorld();
             CraftServer server = ((WorldServer) world).getServer();
             org.bukkit.block.Block block = craftWorld.getBlockAt(i, j, k);
diff --git a/src/main/java/net/minecraft/server/BlockPumpkin.java b/src/main/java/net/minecraft/server/BlockPumpkin.java
index 594e485009..94f00cc745 100644
--- a/src/main/java/net/minecraft/server/BlockPumpkin.java
+++ b/src/main/java/net/minecraft/server/BlockPumpkin.java
@@ -53,7 +53,7 @@ public class BlockPumpkin extends Block {
 
     // Craftbukkit start
     public void a(World world, int i, int j, int k, int l) {
-        if (net.minecraft.server.Block.byId[l].c()) {
+        if (net.minecraft.server.Block.byId[l] != null && net.minecraft.server.Block.byId[l].c()) {
             CraftWorld craftWorld = ((WorldServer) world).getWorld();
             CraftServer server = ((WorldServer) world).getServer();
             org.bukkit.block.Block block = craftWorld.getBlockAt(i, j, k);
diff --git a/src/main/java/net/minecraft/server/BlockSign.java b/src/main/java/net/minecraft/server/BlockSign.java
index 49b3f176f0..eab330de75 100644
--- a/src/main/java/net/minecraft/server/BlockSign.java
+++ b/src/main/java/net/minecraft/server/BlockSign.java
@@ -106,7 +106,7 @@ public class BlockSign extends BlockContainer {
         super.a(world, i, j, k, l);
         
         // Craftbukkit start
-        if (net.minecraft.server.Block.byId[l].c()) {
+        if (net.minecraft.server.Block.byId[l] != null && net.minecraft.server.Block.byId[l].c()) {
             CraftWorld craftWorld = ((WorldServer) world).getWorld();
             CraftServer server = ((WorldServer) world).getServer();
             Block block = craftWorld.getBlockAt(i, j, k);