diff --git a/src/packets.c b/src/packets.c
index 958becd..59c2ebb 100644
--- a/src/packets.c
+++ b/src/packets.c
@@ -315,18 +315,18 @@ int sc_keepAlive (int client_fd) {
 }
 
 // S->C Set Container Slot
-int sc_setContainerSlot (int client_fd, int container, uint16_t slot, uint8_t count, uint16_t item) {
+int sc_setContainerSlot (int client_fd, int window_id, uint16_t slot, uint8_t count, uint16_t item) {
 
   writeVarInt(client_fd,
     1 +
-    sizeVarInt(container) +
+    sizeVarInt(window_id) +
     1 + 2 +
     sizeVarInt(count) +
     (count > 0 ? sizeVarInt(item) + 2 : 0)
   );
   writeByte(client_fd, 0x14);
 
-  writeVarInt(client_fd, container);
+  writeVarInt(client_fd, window_id);
   writeVarInt(client_fd, 0);
   writeUint16(client_fd, slot);
 
@@ -381,12 +381,27 @@ int cs_playerAction (int client_fd) {
 
 }
 
+// S->C Open Screen
+int sc_openScreen (int client_fd, uint8_t window, const char *title, uint16_t length) {
+
+  writeVarInt(client_fd, 1 + 2 * sizeVarInt(window) + 1 + 2 + length);
+  writeByte(client_fd, 0x34);
+
+  writeVarInt(client_fd, window);
+  writeVarInt(client_fd, window);
+
+  writeByte(client_fd, 8); // string nbt tag
+  writeUint16(client_fd, length); // string length
+  send(client_fd, title, length, 0);
+
+}
+
 // C->S Use Item On
 int cs_useItemOn (int client_fd) {
 
   uint8_t hand = readByte(client_fd);
 
-  uint64_t pos = readUint64(client_fd);
+  int64_t pos = readInt64(client_fd);
   int x = pos >> 38;
   int y = pos << 52 >> 52;
   int z = pos << 26 >> 38;
@@ -404,10 +419,17 @@ int cs_useItemOn (int client_fd) {
 
   int sequence = readVarInt(client_fd);
 
+  uint8_t target = getBlockAt(x, y, z);
+  if (target == B_crafting_table) {
+    sc_openScreen(client_fd, 12, "Crafting", 8);
+    return 0;
+  }
+
   PlayerData *player;
   if (getPlayerData(client_fd, &player)) return 1;
 
-  uint8_t block = I_to_B[player->inventory_items[player->hotbar]];
+  uint16_t item = player->inventory_items[player->hotbar];
+  uint8_t block = item == 320 ? B_crafting_table : I_to_B[item]; // hack!!
 
   // if the selected item doesn't correspond to a block, exit
   if (block == 0) return 0;
@@ -454,7 +476,8 @@ int cs_clickContainer (int client_fd) {
 
   for (int i = 0; i < changes_count; i ++) {
 
-    slot = clientSlotToServerSlot(readUint16(client_fd));
+    slot = clientSlotToServerSlot(window_id, readUint16(client_fd));
+    // slots outside of the inventory overflow into the crafting buffer
     if (slot > 40) craft = true;
 
     if (!readByte(client_fd)) { // no item?
diff --git a/src/packets.h b/src/packets.h
index e44d496..fe427b2 100644
--- a/src/packets.h
+++ b/src/packets.h
@@ -22,8 +22,9 @@ int sc_startWaitingForChunks (int client_fd);
 int sc_setCenterChunk (int client_fd, int x, int y);
 int sc_chunkDataAndUpdateLight (int client_fd, int _x, int _z);
 int sc_keepAlive (int client_fd);
-int sc_setContainerSlot (int client_fd, int container, uint16_t slot, uint8_t count, uint16_t item);
+int sc_setContainerSlot (int client_fd, int window_id, uint16_t slot, uint8_t count, uint16_t item);
 int sc_setHeldItem (int client_fd, uint8_t slot);
+int sc_openScreen (int client_fd, uint8_t window, const char *title, uint16_t length);
 int sc_registries(int client_fd);
 
 #endif
diff --git a/src/tools.c b/src/tools.c
index 440f829..8969bc3 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -181,18 +181,30 @@ uint8_t serverSlotToClientSlot (uint8_t slot) {
   return 255;
 }
 
-uint8_t clientSlotToServerSlot (uint8_t slot) {
-  if (slot >= 36 && slot <= 44) return slot - 36;
-  if (slot >= 9 && slot <= 35) return slot;
-  if (slot == 45) return 40;
-  if (slot >= 5 && slot <= 8) return 4 - (slot - 5) + 36;
+uint8_t clientSlotToServerSlot (int window_id, uint8_t slot) {
 
-  // map inventory crafting slots to player data crafting grid (semi-hack)
-  // this abuses the fact that the buffers are adjacent in player data
-  if (slot == 1) return 41;
-  if (slot == 2) return 42;
-  if (slot == 3) return 44;
-  if (slot == 4) return 45;
+  if (window_id == 0) { // player inventory
+
+    if (slot >= 36 && slot <= 44) return slot - 36;
+    if (slot >= 9 && slot <= 35) return slot;
+    if (slot == 45) return 40;
+    if (slot >= 5 && slot <= 8) return 4 - (slot - 5) + 36;
+
+    // map inventory crafting slots to player data crafting grid (semi-hack)
+    // this abuses the fact that the buffers are adjacent in player data
+    if (slot == 1) return 41;
+    if (slot == 2) return 42;
+    if (slot == 3) return 44;
+    if (slot == 4) return 45;
+
+  } else if (window_id == 12) { // crafting table
+
+    // same crafting offset overflow hack as above
+    if (slot >= 1 && slot <= 9) return 40 + slot;
+    // the rest of the slots are identical, just shifted by one
+    if (slot >= 10 && slot <= 45) return clientSlotToServerSlot(0, slot - 1);
+
+  }
 
   return 255;
 }
diff --git a/src/tools.h b/src/tools.h
index 5cd0d90..a60a5c3 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -37,7 +37,7 @@ void clearPlayerFD (int client_fd);
 int givePlayerItem (int client_fd, uint16_t item);
 
 uint8_t serverSlotToClientSlot (uint8_t slot);
-uint8_t clientSlotToServerSlot (uint8_t slot);
+uint8_t clientSlotToServerSlot (int window_id, uint8_t slot);
 
 uint8_t getBlockChange (short x, short y, short z);
 void makeBlockChange (short x, short y, short z, uint8_t block);