diff --git a/protocol/src/protocol/mod.rs b/protocol/src/protocol/mod.rs
index d1b3d02..6bc14c8 100644
--- a/protocol/src/protocol/mod.rs
+++ b/protocol/src/protocol/mod.rs
@@ -34,7 +34,7 @@ use flate2;
 use time;
 use shared::Position;
 
-pub const SUPPORTED_PROTOCOL: i32 = 210;
+pub const SUPPORTED_PROTOCOL: i32 = 315;
 
 
 /// Helper macro for defining packets
@@ -200,7 +200,9 @@ impl <T> Serializable for Option<T> where T : Serializable {
 
 impl Serializable for String {
     fn read_from<R: io::Read>(buf: &mut R) -> Result<String, Error> {
-        let len = try!(VarInt::read_from(buf)).0;
+        let len = VarInt::read_from(buf)?.0;
+        debug_assert!(len >= 0, "Negative string length: {}", len);
+        debug_assert!(len <= 65536, "String length too big: {}", len);
         let mut ret = String::new();
         try!(buf.take(len as u64).read_to_string(&mut ret));
         Result::Ok(ret)
diff --git a/protocol/src/protocol/packet.rs b/protocol/src/protocol/packet.rs
index 2b5f8aa..fb4613f 100644
--- a/protocol/src/protocol/packet.rs
+++ b/protocol/src/protocol/packet.rs
@@ -231,9 +231,9 @@ state_packets!(
                 field location: Position =,
                 field face: VarInt =,
                 field hand: VarInt =,
-                field cursor_x: u8 =,
-                field cursor_y: u8 =,
-                field cursor_z: u8 =,
+                field cursor_x: f32 =,
+                field cursor_y: f32 =,
+                field cursor_z: f32 =,
             }
             /// UseItem is sent when the client tries to use an item.
             packet UseItem {
@@ -281,7 +281,7 @@ state_packets!(
             packet SpawnMob {
                 field entity_id: VarInt =,
                 field uuid: UUID =,
-                field ty: u8 =,
+                field ty: VarInt =,
                 field x: f64 =,
                 field y: f64 =,
                 field z: f64 =,
@@ -780,9 +780,10 @@ state_packets!(
                 field action: VarInt =,
                 field title: Option<format::Component> = when(|p: &Title| p.action.0 == 0),
                 field sub_title: Option<format::Component> = when(|p: &Title| p.action.0 == 1),
-                field fade_in: Option<i32> = when(|p: &Title| p.action.0 == 2),
-                field fade_stay: Option<i32> = when(|p: &Title| p.action.0 == 2),
-                field fade_out: Option<i32> = when(|p: &Title| p.action.0 == 2),
+                field action_bar_text: Option<String> = when(|p: &Title| p.action.0 == 2),
+                field fade_in: Option<i32> = when(|p: &Title| p.action.0 == 3),
+                field fade_stay: Option<i32> = when(|p: &Title| p.action.0 == 3),
+                field fade_out: Option<i32> = when(|p: &Title| p.action.0 == 3),
             }
             /// SoundEffect plays the named sound at the target location.
             packet SoundEffect {
@@ -804,6 +805,7 @@ state_packets!(
             packet CollectItem {
                 field collected_entity_id: VarInt =,
                 field collector_entity_id: VarInt =,
+                field number_of_items: VarInt =,
             }
             /// EntityTeleport teleports the entity to the target location. This is
             /// sent if the entity moves further than EntityMove allows.