diff --git a/crdt-enc-gpgme/Cargo.toml b/crdt-enc-gpgme/Cargo.toml
index 98953b3..3e030cb 100644
--- a/crdt-enc-gpgme/Cargo.toml
+++ b/crdt-enc-gpgme/Cargo.toml
@@ -7,11 +7,11 @@ edition = "2018"
 [dependencies]
 serde = "1"
 serde_bytes = "0.11"
-rmp-serde = "0.14"
+rmp-serde = "0.15"
 async-trait = "0.1"
 anyhow = "1"
 uuid = "0.8"
-crdts = "4"
+crdts = "5"
 gpgme = "0.9"
 dyn-clone = "1"
 
diff --git a/crdt-enc-gpgme/src/lib.rs b/crdt-enc-gpgme/src/lib.rs
index eba93a3..71529b3 100644
--- a/crdt-enc-gpgme/src/lib.rs
+++ b/crdt-enc-gpgme/src/lib.rs
@@ -9,7 +9,7 @@ use crdt_enc::{
 };
 use crdts::{CmRDT, CvRDT, MVReg, Orswot};
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
-use std::{borrow::Cow, fmt::Debug, sync::Mutex as SyncMutex};
+use std::{borrow::Cow, convert::Infallible, fmt::Debug, sync::Mutex as SyncMutex};
 use uuid::Uuid;
 
 pub fn init() {
@@ -48,6 +48,12 @@ pub struct Meta {
 }
 
 impl CvRDT for Meta {
+    type Validation = Infallible;
+
+    fn validate_merge(&self, _other: &Self) -> Result<(), Infallible> {
+        Ok(())
+    }
+
     fn merge(&mut self, other: Self) {
         self.key_fps.merge(other.key_fps);
     }
@@ -117,12 +123,9 @@ impl crdt_enc::key_cryptor::KeyCryptor for KeyHandler {
 
             let read_ctx = data.remote_meta.read();
 
-            let actor = data.info.as_ref().context("info is none")?.actor();
-            let write_ctx = read_ctx.derive_add_ctx(actor);
-
             let mut keys = read_ctx
                 .val
-                .into_iter()
+                .iter()
                 .try_fold(Keys::default(), |mut acc, vb| {
                     // TODO: check version
                     // TODO: decrypt key
@@ -133,6 +136,9 @@ impl crdt_enc::key_cryptor::KeyCryptor for KeyHandler {
 
             keys.merge(new_keys);
 
+            let actor = data.info.as_ref().context("info is none")?.actor();
+            let write_ctx = read_ctx.derive_add_ctx(actor);
+
             let op = data.remote_meta.write(
                 VersionBytes::new(
                     // TODO
diff --git a/crdt-enc-sodium/Cargo.toml b/crdt-enc-sodium/Cargo.toml
index 0a19d7a..14f685c 100644
--- a/crdt-enc-sodium/Cargo.toml
+++ b/crdt-enc-sodium/Cargo.toml
@@ -5,11 +5,11 @@ authors = ["Thomas Heck <t@b128.net>"]
 edition = "2018"
 
 [dependencies]
-crdts = "4"
+crdts = "5"
 sodiumoxide = "0.2"
 anyhow = "1"
 serde = "1"
-rmp-serde = "0.14"
+rmp-serde = "0.15"
 serde_bytes = "0.11"
 uuid = "0.8"
 async-trait = "0.1"
diff --git a/crdt-enc-tokio/Cargo.toml b/crdt-enc-tokio/Cargo.toml
index cb08a45..58303d4 100644
--- a/crdt-enc-tokio/Cargo.toml
+++ b/crdt-enc-tokio/Cargo.toml
@@ -5,22 +5,26 @@ authors = ["Thomas Heck <t@b128.net>"]
 edition = "2018"
 
 [dependencies]
-crdts = "4"
+crdts = "5"
 serde = "1"
 async-trait = "0.1"
 futures = "0.3"
 anyhow = "1"
 uuid = "0.8"
 data-encoding = "2"
-bytes = "0.5"
+bytes = "1"
 
 [dependencies.tiny-keccak]
 version = "2"
 features = ["sha3"]
 
 [dependencies.tokio]
-version = "0.2"
-features = ["fs", "stream", "io-util"]
+version = "1"
+features = ["fs", "io-util"]
+
+[dependencies.tokio-stream]
+version = "0.1"
+features = ["fs"]
 
 [dependencies.crdt-enc]
 path = "../crdt-enc"
diff --git a/crdt-enc-tokio/src/lib.rs b/crdt-enc-tokio/src/lib.rs
index 75fc539..837590b 100644
--- a/crdt-enc-tokio/src/lib.rs
+++ b/crdt-enc-tokio/src/lib.rs
@@ -23,6 +23,7 @@ use tokio::{
     fs,
     io::{self, AsyncWrite, AsyncWriteExt},
 };
+use tokio_stream::wrappers::ReadDirStream;
 use uuid::Uuid;
 
 #[derive(Debug)]
@@ -383,7 +384,7 @@ fn read_dir_optional(path: PathBuf) -> impl Stream<Item = Result<fs::DirEntry>>
     async move {
         match fs::read_dir(&path).await {
             Ok(dir) => {
-                let entry_stream = dir.map(move |entry| {
+                let entry_stream = ReadDirStream::new(dir).map(move |entry| {
                     entry.with_context(|| format!("failed getting entry from {}", path.display()))
                 });
                 Ok(Either::Left(entry_stream))
@@ -413,7 +414,7 @@ async fn write_content_addressible_file(
     let mut digest = Sha3::v256();
     let mut buf = bytes.buf();
     while buf.has_remaining() {
-        let b = buf.bytes();
+        let b = buf.chunk();
         digest.update(b);
         buf.advance(b.len());
     }
diff --git a/crdt-enc/Cargo.toml b/crdt-enc/Cargo.toml
index 18fcaa1..3d2e3e6 100644
--- a/crdt-enc/Cargo.toml
+++ b/crdt-enc/Cargo.toml
@@ -5,16 +5,16 @@ authors = ["Thomas Heck <t@b128.net>"]
 edition = "2018"
 
 [dependencies]
-crdts = "4"
+crdts = "5"
 serde = "1"
 serde_bytes = "0.11"
-rmp-serde = "0.14"
+rmp-serde = "0.15"
 async-trait = "0.1"
 anyhow = "1"
 thiserror = "1"
 futures = "0.3"
 dyn-clone = "1"
-bytes = "0.5"
+bytes = "1"
 
 [dependencies.uuid]
 version = "0.8"
diff --git a/crdt-enc/src/key_cryptor.rs b/crdt-enc/src/key_cryptor.rs
index 9c7cac2..9a899b6 100644
--- a/crdt-enc/src/key_cryptor.rs
+++ b/crdt-enc/src/key_cryptor.rs
@@ -9,6 +9,7 @@ use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::{
     borrow::Borrow,
     cmp::{Eq, Ord, Ordering, PartialEq},
+    convert::Infallible,
     fmt::Debug,
     hash::{Hash, Hasher},
     sync::Arc,
@@ -42,6 +43,12 @@ pub struct Keys {
 }
 
 impl CvRDT for Keys {
+    type Validation = Infallible;
+
+    fn validate_merge(&self, _other: &Self) -> Result<(), Infallible> {
+        Ok(())
+    }
+
     fn merge(&mut self, other: Keys) {
         self.latest_key_id.merge(other.latest_key_id);
         self.keys.merge(other.keys);
diff --git a/crdt-enc/src/lib.rs b/crdt-enc/src/lib.rs
index ee36d9b..605a094 100644
--- a/crdt-enc/src/lib.rs
+++ b/crdt-enc/src/lib.rs
@@ -22,6 +22,7 @@ use futures::{
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::{
     collections::HashSet,
+    convert::Infallible,
     default::Default,
     fmt::Debug,
     mem,
@@ -740,6 +741,12 @@ struct RemoteMeta {
 }
 
 impl CvRDT for RemoteMeta {
+    type Validation = Infallible;
+
+    fn validate_merge(&self, _other: &Self) -> Result<(), Infallible> {
+        Ok(())
+    }
+
     fn merge(&mut self, other: Self) {
         self.storage.merge(other.storage);
         self.cryptor.merge(other.cryptor);
diff --git a/crdt-enc/src/utils.rs b/crdt-enc/src/utils.rs
index 887c8e8..3da10c2 100644
--- a/crdt-enc/src/utils.rs
+++ b/crdt-enc/src/utils.rs
@@ -4,6 +4,7 @@ pub use version_bytes::*;
 
 use crdts::{CmRDT, CvRDT};
 use serde::{Deserialize, Serialize};
+use std::convert::Infallible;
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
 pub struct EmptyCrdt;
@@ -11,9 +12,21 @@ pub struct EmptyCrdt;
 impl CmRDT for EmptyCrdt {
     type Op = ();
 
+    type Validation = Infallible;
+
+    fn validate_op(&self, op: &Self::Op) -> Result<(), Infallible> {
+        Ok(())
+    }
+
     fn apply(&mut self, _op: Self::Op) {}
 }
 
 impl CvRDT for EmptyCrdt {
+    type Validation = Infallible;
+
+    fn validate_merge(&self, _other: &Self) -> Result<(), Infallible> {
+        Ok(())
+    }
+
     fn merge(&mut self, _other: Self) {}
 }
diff --git a/crdt-enc/src/utils/version_bytes.rs b/crdt-enc/src/utils/version_bytes.rs
index 2cc846a..d8f1a1c 100644
--- a/crdt-enc/src/utils/version_bytes.rs
+++ b/crdt-enc/src/utils/version_bytes.rs
@@ -226,7 +226,7 @@ impl<'a> ::bytes::Buf for VersionBytesBuf<'a> {
         BUF_VERSION_LEN_BYTES + self.content.len() - self.pos
     }
 
-    fn bytes(&self) -> &[u8] {
+    fn chunk(&self) -> &[u8] {
         if self.pos < BUF_VERSION_LEN_BYTES {
             &self.version_len[self.pos..]
         } else {
@@ -244,7 +244,7 @@ impl<'a> ::bytes::Buf for VersionBytesBuf<'a> {
         self.pos += cnt;
     }
 
-    fn bytes_vectored<'b>(&'b self, dst: &mut [IoSlice<'b>]) -> usize {
+    fn chunks_vectored<'b>(&'b self, dst: &mut [IoSlice<'b>]) -> usize {
         // TODO: TESTING!
 
         if dst.len() == 0 {
diff --git a/examples/test/Cargo.toml b/examples/test/Cargo.toml
index 4d0236b..b02407a 100644
--- a/examples/test/Cargo.toml
+++ b/examples/test/Cargo.toml
@@ -10,7 +10,7 @@ crdt-enc-tokio = {path="../../crdt-enc-tokio"}
 crdt-enc-sodium = {path="../../crdt-enc-sodium"}
 crdt-enc-gpgme = {path="../../crdt-enc-gpgme"}
 uuid = {version = "0.8", features = ["serde", "v4"]}
-crdts = "4"
-tokio = {version = "0.2", features = ["macros"]}
+crdts = "5"
+tokio = {version = "1", features = ["macros", "rt"]}
 anyhow = "1"
 futures = "0.3"
diff --git a/examples/test/src/main.rs b/examples/test/src/main.rs
index 1f75c5f..ca95c32 100644
--- a/examples/test/src/main.rs
+++ b/examples/test/src/main.rs
@@ -7,7 +7,7 @@ use uuid::Uuid;
 
 const CURRENT_DATA_VERSION: Uuid = Uuid::from_u128(1u128);
 
-#[tokio::main]
+#[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<()> {
     crdt_enc_sodium::init();
 
@@ -44,8 +44,8 @@ async fn main() -> Result<()> {
 
     let op = repo.with_state(|s: &crdts::MVReg<u64, Uuid>| {
         let read_ctx = s.read();
-        let add_ctx = read_ctx.derive_add_ctx(info.actor());
-        let op = s.write(read_ctx.val.into_iter().max().unwrap_or(0) + 1, add_ctx);
+        let new_val = read_ctx.val.iter().copied().max().unwrap_or(0) + 1;
+        let op = s.write(new_val, read_ctx.derive_add_ctx(info.actor()));
         Ok(op)
     })?;