diff --git a/Cargo.toml b/Cargo.toml
index ce66a71..d6483f9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "democutter"
 version = "0.1.0"
 authors = ["Robin Appelman <robin@icewind.nl>"]
-edition = "2018"
+edition = "2021"
 
 [lib]
 crate-type = ["cdylib", "rlib"]
@@ -16,7 +16,7 @@ default = ["console_error_panic_hook"]
 
 [dependencies]
 bitbuffer = "0.10"
-tf-demo-parser = { version = "0.3", path = "../tf-demo-parser" }
+tf-demo-parser = { version = "0.4", path = "../tf-demo-parser" }
 wasm-bindgen = "0.2.63"
 web-sys = { version = "0.3", features = ["console"] }
 
@@ -38,5 +38,5 @@ wasm-bindgen-test = "0.3.13"
 
 [profile.release]
 
-[profile.dev.overrides."*"]
+[profile.dev.package."*"]
 opt-level = 3
\ No newline at end of file
diff --git a/src/entity.rs b/src/entity.rs
index 6010b0a..5024a18 100644
--- a/src/entity.rs
+++ b/src/entity.rs
@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::iter::once;
 use std::mem::replace;
 use tf_demo_parser::demo::message::packetentities::{
     EntityId, PacketEntitiesMessage, PacketEntity, PVS,
@@ -7,6 +8,7 @@ use tf_demo_parser::ParserState;
 
 #[derive(Default)]
 pub struct ActiveEntities {
+    baselines: [HashMap<EntityId, PacketEntity>; 2],
     entities: HashMap<EntityId, PacketEntity>,
 }
 
@@ -22,49 +24,73 @@ impl ActiveEntities {
         for deleted in msg.removed_entities.iter() {
             self.entities.remove(deleted);
         }
+        if msg.updated_base_line {
+            let old_index = msg.base_line as usize;
+            let new_index = 1 - old_index;
+            self.baselines.swap(0, 1);
+
+            for entity in &msg.entities {
+                if entity.pvs == PVS::Enter {
+                    self.baselines[new_index].insert(entity.entity_index, entity.clone());
+                }
+            }
+        }
     }
 
     fn handle_entity(&mut self, entity: &PacketEntity, state: &ParserState) {
-        if entity.pvs == PVS::Enter {
-            self.entities.insert(entity.entity_index, entity.clone());
-        } else {
-            self.entities
-                .entry(entity.entity_index)
-                .and_modify(|existing| update_entity(existing, entity, state))
-                .or_insert_with(|| entity.clone());
-        }
+        self.entities
+            .entry(entity.entity_index)
+            .and_modify(|existing| update_entity(existing, entity, state))
+            .or_insert_with(|| entity.clone());
     }
 
-    pub fn encode(self) -> PacketEntitiesMessage {
-        let max_entries = self.entities.len() as u16;
+    pub fn encode(self) -> impl IntoIterator<Item = PacketEntitiesMessage> {
+        let mut baselines = [
+            encode_entities(self.baselines[0].clone().into_values().collect::<Vec<_>>()),
+            encode_entities(self.baselines[1].clone().into_values().collect::<Vec<_>>()),
+        ];
+        let entities = encode_entities(self.entities.into_values().collect::<Vec<_>>());
 
-        let mut entities = self
-            .entities
-            .into_iter()
-            .map(|(_k, v)| v)
-            .collect::<Vec<_>>();
-        entities.sort_by(|a, b| a.entity_index.cmp(&b.entity_index));
+        baselines[0].updated_base_line = true;
+        baselines[0].base_line = 1; //the baseline that is updated is the other one
 
-        PacketEntitiesMessage {
-            entities,
-            removed_entities: vec![],
-            max_entries,
-            delta: None,
-            base_line: 0,
-            updated_base_line: false,
-        }
+        baselines[1].updated_base_line = true;
+
+        baselines.into_iter().chain(once(entities))
+    }
+}
+
+fn encode_entities(mut entities: Vec<PacketEntity>) -> PacketEntitiesMessage {
+    entities.sort_by(|a, b| a.entity_index.cmp(&b.entity_index));
+    let max_entries = entities.len() as u16;
+    PacketEntitiesMessage {
+        entities,
+        removed_entities: vec![],
+        max_entries,
+        delta: None,
+        base_line: 0,
+        updated_base_line: false,
     }
 }
 
 fn update_entity(old: &mut PacketEntity, new: &PacketEntity, _state: &ParserState) {
-    for prop in &new.props {
-        match old
-            .props
-            .iter_mut()
-            .find(|existing| existing.index == prop.index)
-        {
-            Some(existing) => existing.value = prop.value.clone(),
-            None => old.props.push(prop.clone()),
+    if old.serial_number != new.serial_number {
+        *old = new.clone();
+        old.pvs = PVS::Enter;
+    } else {
+        assert_eq!(
+            _state.server_classes[usize::from(old.server_class)],
+            _state.server_classes[usize::from(new.server_class)]
+        );
+        for prop in &new.props {
+            match old
+                .props
+                .iter_mut()
+                .find(|existing| existing.index == prop.index)
+            {
+                Some(existing) => existing.value = prop.value.clone(),
+                None => old.props.push(prop.clone()),
+            }
         }
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index dd54678..786bf02 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -25,7 +25,7 @@ use web_sys::console;
 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
 const PRESERVE_PACKETS: &[PacketType] = &[
-    PacketType::Sigon,
+    PacketType::Signon,
     PacketType::DataTables,
     PacketType::StringTables,
     PacketType::SyncTick,
@@ -82,17 +82,16 @@ pub fn cut(input: &[u8], start_tick: u32, end_tick: u32) -> Vec<u8> {
             panic!("first packet is not a MessagePacket")
         }
 
-        let msg = entities.encode();
+        let msgs = entities.encode().into_iter().map(Message::PacketEntities);
         let packet = Packet::Message(MessagePacket {
             tick: 0,
-            messages: vec![
-                Message::NetTick(NetTickMessage {
-                    tick: delta_tick,
-                    frame_time: 1881,
-                    std_dev: 263,
-                }),
-                Message::PacketEntities(msg),
-            ],
+            messages: once(Message::NetTick(NetTickMessage {
+                tick: delta_tick,
+                frame_time: 1881,
+                std_dev: 263,
+            }))
+            .chain(msgs)
+            .collect(),
             meta: MessagePacketMeta {
                 flags: 0,
                 view_angles: Default::default(),