diff --git a/MCGalaxy/Network/Packets/Packet.cs b/MCGalaxy/Network/Packets/Packet.cs
index 19f3c87a5..58e6adbb5 100644
--- a/MCGalaxy/Network/Packets/Packet.cs
+++ b/MCGalaxy/Network/Packets/Packet.cs
@@ -718,7 +718,7 @@ public static byte[] DefineBlock(BlockDefinition def, bool hasCP437,
             int i = 0;
             buffer[i++] = Opcode.CpeDefineBlock;
             MakeDefineBlockStart(def, buffer, ref i, false, hasCP437, extBlocks, extTexs);
-            buffer[i++] = def.Shape;
+            buffer[i++] = def.Shape == 0 ? 0 : def.MaxY;
             MakeDefineBlockEnd(def, ref i, buffer);
             return buffer;
         }