diff --git a/Cargo.lock b/Cargo.lock
index 921a40e8..ec91a1c4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,17 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "ahash"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "991984e3fd003e7ba02eb724f87a0f997b78677c46c0e91f8424ad7394c9886a"
+dependencies = [
+ "getrandom 0.2.3",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.18"
@@ -59,6 +70,12 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2dabbe35f96fb9507f7330793dc490461b2962659ac5d427181e451a623751d1"
 
+[[package]]
+name = "bech32"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf9ff0bbfd639f15c74af777d81383cf53efb7c93613f6cab67c6c11e05bbf8b"
+
 [[package]]
 name = "bip39"
 version = "0.1.0"
@@ -96,7 +113,7 @@ checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 [[package]]
 name = "cardano-legacy-address"
 version = "0.1.1"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
  "cbor_event",
  "chain-ser",
@@ -137,9 +154,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 [[package]]
 name = "chain-addr"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
- "bech32",
+ "bech32 0.8.1",
  "chain-core",
  "chain-crypto",
  "cryptoxide",
@@ -148,7 +165,7 @@ dependencies = [
 [[package]]
 name = "chain-core"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
  "chain-ser",
 ]
@@ -156,9 +173,9 @@ dependencies = [
 [[package]]
 name = "chain-crypto"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
- "bech32",
+ "bech32 0.8.1",
  "cryptoxide",
  "curve25519-dalek-ng",
  "digest",
@@ -175,7 +192,7 @@ dependencies = [
 [[package]]
 name = "chain-impl-mockchain"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
  "cardano-legacy-address",
  "chain-addr",
@@ -209,14 +226,13 @@ dependencies = [
 [[package]]
 name = "chain-ser"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 
 [[package]]
 name = "chain-time"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
- "cfg-if 1.0.0",
  "chain-core",
  "chain-ser",
 ]
@@ -224,7 +240,7 @@ dependencies = [
 [[package]]
 name = "chain-vote"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
  "cfg-if 1.0.0",
  "chain-core",
@@ -481,6 +497,24 @@ version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0a01e0497841a3b2db4f8afa483cce65f7e96a3498bd6c541734792aeac8fe7"
 
+[[package]]
+name = "hashbrown"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+dependencies = [
+ "ahash",
+]
+
+[[package]]
+name = "hashlink"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7249a3129cbc1ffccd74857f81464a323a152173cdb134e0fd81bc803b29facf"
+dependencies = [
+ "hashbrown",
+]
+
 [[package]]
 name = "hdkeygen"
 version = "0.2.0"
@@ -526,7 +560,7 @@ checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 [[package]]
 name = "imhamt"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 dependencies = [
  "thiserror",
 ]
@@ -652,6 +686,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
+
 [[package]]
 name = "opaque-debug"
 version = "0.3.0"
@@ -908,7 +948,7 @@ checksum = "c19772be3c4dd2ceaacf03cb41d5885f2a02c4d8804884918e3a258480803335"
 [[package]]
 name = "sparse-array"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 
 [[package]]
 name = "strum"
@@ -1011,7 +1051,7 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 [[package]]
 name = "typed-bytes"
 version = "0.1.0"
-source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#988528564f6e11db28709b8995587cc499f7c1d2"
+source = "git+https://github.com/input-output-hk/chain-libs.git?branch=master#39e1f7f4e3d76df61bfbc24d8ce4b72a02c9ecc4"
 
 [[package]]
 name = "typenum"
@@ -1087,6 +1127,7 @@ dependencies = [
  "chain-time",
  "cryptoxide",
  "ed25519-bip32",
+ "hashlink",
  "hdkeygen",
  "hex",
  "imhamt",
@@ -1100,7 +1141,7 @@ dependencies = [
 name = "wallet-core"
 version = "0.7.0-pre3"
 dependencies = [
- "bech32",
+ "bech32 0.7.3",
  "bip39",
  "chain-addr",
  "chain-core",
@@ -1131,7 +1172,7 @@ dependencies = [
 name = "wallet-js"
 version = "0.7.0-pre3"
 dependencies = [
- "bech32",
+ "bech32 0.7.3",
  "chain-crypto",
  "chain-impl-mockchain",
  "chain-vote",
diff --git a/bindings/wallet-core/src/wallet.rs b/bindings/wallet-core/src/wallet.rs
index 240d1cef..f6f420e2 100644
--- a/bindings/wallet-core/src/wallet.rs
+++ b/bindings/wallet-core/src/wallet.rs
@@ -131,7 +131,7 @@ impl Wallet {
             Block::read(&mut block0_bytes).map_err(|e| Error::invalid_input("block0").with(e))?;
 
         let settings = wallet::Settings::new(&block0).unwrap();
-        for fragment in block0.contents.iter() {
+        for fragment in block0.contents().iter() {
             self.free_keys.check_fragment(&fragment.hash(), fragment);
             self.account.check_fragment(&fragment.hash(), fragment);
 
diff --git a/wallet/src/blockchain.rs b/wallet/src/blockchain.rs
index 5a33f006..69358e8c 100644
--- a/wallet/src/blockchain.rs
+++ b/wallet/src/blockchain.rs
@@ -23,8 +23,8 @@ pub struct Settings {
 
 impl Settings {
     pub fn new(block: &Block) -> Result<Self, Error> {
-        let header_id = block.header.id();
-        let ledger = Ledger::new(header_id, block.contents.iter())?;
+        let header_id = block.header().id();
+        let ledger = Ledger::new(header_id, block.contents().iter())?;
 
         let static_parameters = ledger.get_static_parameters().clone();
         let parameters = ledger.get_ledger_parameters();
@@ -37,7 +37,7 @@ impl Settings {
         // fixed in Ledger::new (or at least checked).
         let mut slot_duration = None;
 
-        for fragment in block.contents.iter() {
+        for fragment in block.contents().iter() {
             if let Fragment::Initial(initials) = fragment {
                 for initial in initials.iter() {
                     match initial {
diff --git a/wallet/tests/utils/mod.rs b/wallet/tests/utils/mod.rs
index f8c1be2d..e409a1d2 100644
--- a/wallet/tests/utils/mod.rs
+++ b/wallet/tests/utils/mod.rs
@@ -19,7 +19,7 @@ impl State {
     {
         let mut block0_bytes = ReadBuf::from(block0_bytes.as_ref());
         let block0 = Block::read(&mut block0_bytes).expect("valid block0");
-        let hh = block0.header.id();
+        let hh = block0.header().id();
         let ledger = Ledger::new(hh, block0.fragments()).unwrap();
 
         Self { block0, ledger }
@@ -27,7 +27,7 @@ impl State {
 
     #[allow(dead_code)]
     pub fn initial_contents(&self) -> impl Iterator<Item = &'_ Fragment> {
-        self.block0.contents.iter()
+        self.block0.contents().iter()
     }
 
     pub fn settings(&self) -> Result<Settings, LedgerError> {