diff --git a/Cargo.lock b/Cargo.lock
index 48534de6..79720f8c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -720,9 +720,9 @@ dependencies = [
 
 [[package]]
 name = "hugr"
-version = "0.10.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "daa4ecfcad4aaf337f974e196e0b79ac9288a19535a5b57c9c77f0aaed1d0c6a"
+checksum = "888ee8f56c9e2788b9d74162e2d057426fae9d5cfe4167c415c20260754ea433"
 dependencies = [
  "hugr-core",
  "hugr-passes",
@@ -730,9 +730,9 @@ dependencies = [
 
 [[package]]
 name = "hugr-core"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7de0f6d5bd8ce765a989d928a773b6816b89051bdf1da55d27ac2b6965fa0e07"
+checksum = "ff8a7da4d5b36861d0695e7b9bc3120099bc2b579642e33886022b3e65c92d16"
 dependencies = [
  "bitvec",
  "cgmath",
@@ -749,6 +749,7 @@ dependencies = [
  "petgraph",
  "portgraph 0.12.2",
  "regex",
+ "semver",
  "serde",
  "serde_json",
  "smol_str",
@@ -760,9 +761,9 @@ dependencies = [
 
 [[package]]
 name = "hugr-passes"
-version = "0.6.2"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "31c601b2bc2168e841cb1087f2f7d383a4cace5c9926e10e79e2dd4829cd6758"
+checksum = "75f2dd0e0c842e9513532b3025420dfdb5fed2db511cc83c749f964b25982bc8"
 dependencies = [
  "hugr-core",
  "itertools 0.13.0",
@@ -1515,6 +1516,9 @@ name = "semver"
 version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61697e0a1c7e512e84a621326239844a24d8207b4669b41bc18b32ea5cbf988b"
+dependencies = [
+ "serde",
+]
 
 [[package]]
 name = "serde"
diff --git a/Cargo.toml b/Cargo.toml
index 3a8e3cc4..e9dc4c38 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,8 +26,8 @@ missing_docs = "warn"
 [workspace.dependencies]
 
 # Make sure to run `just recompile-eccs` if the hugr serialisation format changes.
-hugr = "0.10.0"
-hugr-core = "0.7.0"
+hugr = "0.11.0"
+hugr-core = "0.8.0"
 portgraph = "0.12"
 pyo3 = "0.21.2"
 itertools = "0.13.0"
diff --git a/poetry.lock b/poetry.lock
index c2dd79e2..40781175 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -178,17 +178,19 @@ test = ["coverage", "pytest (>=7,<8.1)", "pytest-cov", "pytest-mock (>=3)"]
 
 [[package]]
 name = "hugr"
-version = "0.5.0"
+version = "0.6.0"
 description = "Quantinuum's common representation for quantum programs"
 optional = false
 python-versions = ">=3.10"
 files = [
-    {file = "hugr-0.5.0-py3-none-any.whl", hash = "sha256:7e6c6660e3c7143dd5b89bf429e3ccc68add0d329db4ac35076e7692d2899326"},
-    {file = "hugr-0.5.0.tar.gz", hash = "sha256:c362e19e6842c89d00c9eab8e3afe161a380459ecb212374ecb78e4081964f15"},
+    {file = "hugr-0.6.0-py3-none-any.whl", hash = "sha256:fd08362a2d7723eacd9aecd47b1a9fc6e9434dc1edbd0b97e81df6c53bcbdc9e"},
+    {file = "hugr-0.6.0.tar.gz", hash = "sha256:6070503d5b01b2a8abfe4152cb023661e92cecec4c881793be6263f86435bf2f"},
 ]
 
 [package.dependencies]
 pydantic = ">=2.7,<2.9"
+pydantic-extra-types = ">=2.9.0,<3.0.0"
+semver = ">=3.0.2,<4.0.0"
 
 [[package]]
 name = "hypothesis"
@@ -721,6 +723,28 @@ files = [
 [package.dependencies]
 typing-extensions = ">=4.6.0,<4.7.0 || >4.7.0"
 
+[[package]]
+name = "pydantic-extra-types"
+version = "2.9.0"
+description = "Extra Pydantic types."
+optional = false
+python-versions = ">=3.8"
+files = [
+    {file = "pydantic_extra_types-2.9.0-py3-none-any.whl", hash = "sha256:f0bb975508572ba7bf3390b7337807588463b7248587e69f43b1ad7c797530d0"},
+    {file = "pydantic_extra_types-2.9.0.tar.gz", hash = "sha256:e061c01636188743bb69f368dcd391f327b8cfbfede2fe1cbb1211b06601ba3b"},
+]
+
+[package.dependencies]
+pydantic = ">=2.5.2"
+
+[package.extras]
+all = ["pendulum (>=3.0.0,<4.0.0)", "phonenumbers (>=8,<9)", "pycountry (>=23)", "python-ulid (>=1,<2)", "python-ulid (>=1,<3)", "pytz (>=2024.1)", "semver (>=3.0.2)", "tzdata (>=2024.1)"]
+pendulum = ["pendulum (>=3.0.0,<4.0.0)"]
+phonenumbers = ["phonenumbers (>=8,<9)"]
+pycountry = ["pycountry (>=23)"]
+python-ulid = ["python-ulid (>=1,<2)", "python-ulid (>=1,<3)"]
+semver = ["semver (>=3.0.2)"]
+
 [[package]]
 name = "pytest"
 version = "8.3.2"
@@ -942,6 +966,17 @@ dev = ["cython-lint (>=0.12.2)", "doit (>=0.36.0)", "mypy (==1.10.0)", "pycodest
 doc = ["jupyterlite-pyodide-kernel", "jupyterlite-sphinx (>=0.13.1)", "jupytext", "matplotlib (>=3.5)", "myst-nb", "numpydoc", "pooch", "pydata-sphinx-theme (>=0.15.2)", "sphinx (>=5.0.0)", "sphinx-design (>=0.4.0)"]
 test = ["Cython", "array-api-strict", "asv", "gmpy2", "hypothesis (>=6.30)", "meson", "mpmath", "ninja", "pooch", "pytest", "pytest-cov", "pytest-timeout", "pytest-xdist", "scikit-umfpack", "threadpoolctl"]
 
+[[package]]
+name = "semver"
+version = "3.0.2"
+description = "Python helper for Semantic Versioning (https://semver.org)"
+optional = false
+python-versions = ">=3.7"
+files = [
+    {file = "semver-3.0.2-py3-none-any.whl", hash = "sha256:b1ea4686fe70b981f85359eda33199d60c53964284e0cfb4977d243e37cf4bf4"},
+    {file = "semver-3.0.2.tar.gz", hash = "sha256:6253adb39c70f6e51afed2fa7152bcd414c411286088fb4b9effb133885ab4cc"},
+]
+
 [[package]]
 name = "setuptools"
 version = "72.1.0"
@@ -988,7 +1023,7 @@ dev = ["hypothesis (>=6.70.0)", "pytest (>=7.1.0)"]
 
 [[package]]
 name = "tket2-eccs"
-version = "0.1.0a4"
+version = "0.1.0"
 description = "Precompiled rewrite sets for the tket 2 compiler"
 optional = false
 python-versions = "^3.10"
@@ -1044,4 +1079,4 @@ test = ["covdefaults (>=2.3)", "coverage (>=7.2.7)", "coverage-enable-subprocess
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.10"
-content-hash = "b95cccc876bf1e0b33d1790780d84a50001dfffa49a516c3386d309243fe37cf"
+content-hash = "d65274422e54bbb3c1a61bc7a584ac8584b5d0bac5874533a953524a2e4f3769"
diff --git a/pyproject.toml b/pyproject.toml
index cc3d438d..7c015fea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,7 +32,7 @@ python = "^3.10"
 # https://github.com/python-poetry/poetry/issues/3332
 tket2_eccs = { path = "tket2-eccs", develop = true }
 pytket = "1.31.1"
-hugr = "^0.5.0"
+hugr = "^0.6.0"
 
 [tool.poetry.group.dev.dependencies]
 maturin = "^1.7.0"
@@ -77,7 +77,7 @@ license = { file = "LICENCE" }
 # Note: Be sure to update the dependency versions in [tool.poetry.dependencies] as well
 dependencies = [
     'pytket >= 1.29.2, < 2',
-    'hugr >= 0.5.0, < 0.6',
+    'hugr >= 0.6.0, < 0.7',
     'tket2_eccs >= 0.1.0, < 0.2',
 ]
 
diff --git a/test_files/eccs/nam_4_2.rwr b/test_files/eccs/nam_4_2.rwr
index 84858952..22ab3f52 100644
Binary files a/test_files/eccs/nam_4_2.rwr and b/test_files/eccs/nam_4_2.rwr differ
diff --git a/test_files/eccs/nam_6_3.rwr b/test_files/eccs/nam_6_3.rwr
index f3680602..66961a72 100644
Binary files a/test_files/eccs/nam_6_3.rwr and b/test_files/eccs/nam_6_3.rwr differ
diff --git a/test_files/eccs/small_eccs.rwr b/test_files/eccs/small_eccs.rwr
index da60153c..45230ed4 100644
Binary files a/test_files/eccs/small_eccs.rwr and b/test_files/eccs/small_eccs.rwr differ
diff --git a/tket2-eccs/src/tket2_eccs/data/nam_6_3.rwr b/tket2-eccs/src/tket2_eccs/data/nam_6_3.rwr
index f3680602..66961a72 100644
Binary files a/tket2-eccs/src/tket2_eccs/data/nam_6_3.rwr and b/tket2-eccs/src/tket2_eccs/data/nam_6_3.rwr differ
diff --git a/tket2-hseries/src/extension/futures.rs b/tket2-hseries/src/extension/futures.rs
index d7378231..4fb4bb22 100644
--- a/tket2-hseries/src/extension/futures.rs
+++ b/tket2-hseries/src/extension/futures.rs
@@ -11,7 +11,7 @@ use hugr::{
             OpLoadError,
         },
         ExtensionBuildError, ExtensionId, ExtensionRegistry, OpDef, SignatureError, SignatureFunc,
-        TypeDef,
+        TypeDef, Version,
     },
     ops::{custom::ExtensionOp, NamedOp, OpType},
     types::{type_param::TypeParam, CustomType, PolyFuncType, Signature, Type, TypeArg, TypeBound},
@@ -24,11 +24,13 @@ use strum_macros::{EnumIter, EnumString, IntoStaticStr};
 
 /// The ID of the `tket2.futures` extension.
 pub const EXTENSION_ID: ExtensionId = ExtensionId::new_unchecked("tket2.futures");
+/// The "tket2.futures" extension version
+pub const EXTENSION_VERSION: Version = Version::new(0, 1, 0);
 
 lazy_static! {
     /// The "tket2.futures" extension.
     pub static ref EXTENSION: Extension = {
-        let mut ext = Extension::new(EXTENSION_ID);
+        let mut ext = Extension::new(EXTENSION_ID, EXTENSION_VERSION);
         let _ = add_future_type_def(&mut ext).unwrap();
 
         FutureOpDef::load_all_ops(&mut ext).unwrap();
diff --git a/tket2-hseries/src/extension/quantum_lazy.rs b/tket2-hseries/src/extension/quantum_lazy.rs
index 72dc3f11..02ec4fe7 100644
--- a/tket2-hseries/src/extension/quantum_lazy.rs
+++ b/tket2-hseries/src/extension/quantum_lazy.rs
@@ -8,7 +8,7 @@ use hugr::{
     extension::{
         prelude::{BOOL_T, QB_T},
         simple_op::{try_from_name, MakeOpDef, MakeRegisteredOp, OpLoadError},
-        ExtensionId, ExtensionRegistry, OpDef, SignatureFunc, PRELUDE,
+        ExtensionId, ExtensionRegistry, OpDef, SignatureFunc, Version, PRELUDE,
     },
     ops::{NamedOp as _, OpType},
     types::Signature,
@@ -24,11 +24,13 @@ use super::futures::future_type;
 
 /// The "tket2.quantum.lazy" extension id.
 pub const EXTENSION_ID: ExtensionId = ExtensionId::new_unchecked("tket2.quantum.lazy");
+/// The "tket2.quantum.lazy" extension version.
+pub const EXTENSION_VERSION: Version = Version::new(0, 1, 0);
 
 lazy_static! {
     /// The "tket2.quantum.lazy" extension.
     pub static ref EXTENSION: Extension = {
-        let mut ext = Extension::new(EXTENSION_ID);
+        let mut ext = Extension::new(EXTENSION_ID, EXTENSION_VERSION);
         LazyQuantumOp::load_all_ops(&mut ext).unwrap();
         ext
     };
diff --git a/tket2-hseries/src/extension/result.rs b/tket2-hseries/src/extension/result.rs
index b0264693..ff0e7e35 100644
--- a/tket2-hseries/src/extension/result.rs
+++ b/tket2-hseries/src/extension/result.rs
@@ -7,7 +7,7 @@ use hugr::{
     extension::{
         prelude::{self, BOOL_T, PRELUDE},
         simple_op::{try_from_name, MakeExtensionOp, MakeOpDef, MakeRegisteredOp, OpLoadError},
-        ExtensionId, ExtensionRegistry, ExtensionSet, OpDef, SignatureFunc,
+        ExtensionId, ExtensionRegistry, ExtensionSet, OpDef, SignatureFunc, Version,
     },
     ops::{CustomOp, NamedOp, OpType},
     std_extensions::arithmetic::{
@@ -30,11 +30,13 @@ use strum_macros::{EnumIter, EnumString, IntoStaticStr};
 
 /// The "tket2.result" extension id.
 pub const EXTENSION_ID: ExtensionId = ExtensionId::new_unchecked("tket2.result");
+/// The "tket2.result" extension version.
+pub const EXTENSION_VERSION: Version = Version::new(0, 1, 0);
 
 lazy_static! {
     /// The "tket2.result" extension.
     pub static ref EXTENSION: Extension = {
-        let mut ext = Extension::new_with_reqs(EXTENSION_ID, ExtensionSet::from_iter([INT_EXTENSION_ID, FLOAT_EXTENSION_ID]));
+        let mut ext = Extension::new(EXTENSION_ID, EXTENSION_VERSION).with_reqs(ExtensionSet::from_iter([INT_EXTENSION_ID, FLOAT_EXTENSION_ID]));
         ResultOpDef::load_all_ops(&mut ext).unwrap();
         ext
     };
diff --git a/tket2/src/extension.rs b/tket2/src/extension.rs
index 7636b8fe..b27dd67b 100644
--- a/tket2/src/extension.rs
+++ b/tket2/src/extension.rs
@@ -6,7 +6,9 @@ use crate::serialize::pytket::OpaqueTk1Op;
 use crate::Tk2Op;
 use hugr::extension::prelude::PRELUDE;
 use hugr::extension::simple_op::MakeOpDef;
-use hugr::extension::{CustomSignatureFunc, ExtensionId, ExtensionRegistry, SignatureError};
+use hugr::extension::{
+    CustomSignatureFunc, ExtensionId, ExtensionRegistry, SignatureError, Version,
+};
 use hugr::hugr::IdentList;
 use hugr::std_extensions::arithmetic::float_types::{EXTENSION as FLOAT_EXTENSION, FLOAT64_TYPE};
 use hugr::types::type_param::{TypeArg, TypeParam};
@@ -27,6 +29,9 @@ pub const TKET1_OP_NAME: SmolStr = SmolStr::new_inline("TKET1 Json Op");
 /// The ID of an opaque TKET1 operation metadata.
 pub const TKET1_PAYLOAD_NAME: SmolStr = SmolStr::new_inline("TKET1 Json Payload");
 
+/// Current version of the TKET 1 extension
+pub const TKET1_EXTENSION_VERSION: Version = Version::new(0, 1, 0);
+
 lazy_static! {
 /// A custom type for the encoded TKET1 operation
 pub static ref TKET1_OP_PAYLOAD : CustomType =
@@ -34,7 +39,7 @@ pub static ref TKET1_OP_PAYLOAD : CustomType =
 
 /// The TKET1 extension, containing the opaque TKET1 operations.
 pub static ref TKET1_EXTENSION: Extension = {
-    let mut res = Extension::new(TKET1_EXTENSION_ID);
+    let mut res = Extension::new(TKET1_EXTENSION_ID, TKET1_EXTENSION_VERSION);
 
     let tket1_op_payload = TypeParam::String;
     res.add_op(
@@ -94,6 +99,9 @@ pub const SYM_EXPR_NAME: SmolStr = SmolStr::new_inline("SymExpr");
 /// The name of the symbolic expression opaque type arg.
 pub const SYM_OP_ID: SmolStr = SmolStr::new_inline("symbolic_float");
 
+/// Current version of the TKET 2 extension
+pub const TKET2_EXTENSION_VERSION: Version = Version::new(0, 1, 0);
+
 lazy_static! {
 /// The type of the symbolic expression opaque type arg.
 pub static ref SYM_EXPR_T: CustomType =
@@ -101,7 +109,7 @@ pub static ref SYM_EXPR_T: CustomType =
 
 /// The extension definition for TKET2 ops and types.
 pub static ref TKET2_EXTENSION: Extension = {
-    let mut e = Extension::new(TKET2_EXTENSION_ID);
+    let mut e = Extension::new(TKET2_EXTENSION_ID, TKET2_EXTENSION_VERSION);
     Tk2Op::load_all_ops(&mut e).expect("add fail");
 
     e.add_op(
diff --git a/tket2/src/passes/pytket.rs b/tket2/src/passes/pytket.rs
index 87c7ecb8..33bd552c 100644
--- a/tket2/src/passes/pytket.rs
+++ b/tket2/src/passes/pytket.rs
@@ -49,7 +49,7 @@ mod test {
         Container, Dataflow, DataflowSubContainer, HugrBuilder, ModuleBuilder, SubContainer,
     };
     use hugr::extension::prelude::QB_T;
-    use hugr::extension::{ExtensionSet, PRELUDE_REGISTRY};
+    use hugr::extension::PRELUDE_REGISTRY;
     use hugr::ops::handle::NodeHandle;
     use hugr::ops::{MakeTuple, OpType, Tag, UnpackTuple};
     use hugr::types::{Signature, TypeRow};
@@ -74,11 +74,7 @@ mod test {
                 let [q1, q2] = func.input_wires_arr();
 
                 let cfg = {
-                    let mut cfg = func.cfg_builder(
-                        [(QB_T, q1), (QB_T, q2)],
-                        two_qbs.clone(),
-                        ExtensionSet::new(),
-                    )?;
+                    let mut cfg = func.cfg_builder([(QB_T, q1), (QB_T, q2)], two_qbs.clone())?;
 
                     circ = {
                         let mut dfg = cfg.simple_entry_builder(two_qbs.clone(), 1)?;