diff --git a/Cargo.lock b/Cargo.lock
index 6017e8600..bb30ddd3a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1632,15 +1632,6 @@ dependencies = [
  "serde_core",
 ]
 
-[[package]]
-name = "indoc"
-version = "2.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79cf5c93f93228cf8efb3ba362535fb11199ac548a09ce117c9b1adc3030d706"
-dependencies = [
- "rustversion",
-]
-
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.2"
@@ -1801,15 +1792,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "memoffset"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "minicov"
 version = "0.3.8"
@@ -2227,34 +2209,21 @@ dependencies = [
  "pumpkin-constraints",
  "pumpkin-solver",
  "pyo3",
- "pyo3-build-config 0.28.3",
+ "pyo3-build-config",
 ]
 
 [[package]]
 name = "pyo3"
-version = "0.25.1"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8970a78afe0628a3e3430376fc5fd76b6b45c4d43360ffd6cdd40bdde72b682a"
+checksum = "91fd8e38a3b50ed1167fb981cd6fd60147e091784c427b8f7183a7ee32c31c12"
 dependencies = [
- "indoc",
  "libc",
- "memoffset",
  "once_cell",
  "portable-atomic",
- "pyo3-build-config 0.25.1",
+ "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
- "unindent",
-]
-
-[[package]]
-name = "pyo3-build-config"
-version = "0.25.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "458eb0c55e7ece017adeba38f2248ff3ac615e53660d7c71a238d7d2a01c7598"
-dependencies = [
- "once_cell",
- "target-lexicon",
 ]
 
 [[package]]
@@ -2268,19 +2237,19 @@ dependencies = [
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.25.1"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7114fe5457c61b276ab77c5055f206295b812608083644a5c5b2640c3102565c"
+checksum = "7f29e10af80b1f7ccaf7f69eace800a03ecd13e883acfacc1e5d0988605f651e"
 dependencies = [
  "libc",
- "pyo3-build-config 0.25.1",
+ "pyo3-build-config",
 ]
 
 [[package]]
 name = "pyo3-macros"
-version = "0.25.1"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a8725c0a622b374d6cb051d11a0983786448f7785336139c3c94f5aa6bef7e50"
+checksum = "df6e520eff47c45997d2fc7dd8214b25dd1310918bbb2642156ef66a67f29813"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -2290,13 +2259,13 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.25.1"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4109984c22491085343c05b0dbc54ddc405c3cf7b4374fc533f5c3313a572ccc"
+checksum = "c4cdc218d835738f81c2338f822078af45b4afdf8b2e33cbb5916f108b813acb"
 dependencies = [
  "heck",
  "proc-macro2",
- "pyo3-build-config 0.25.1",
+ "pyo3-build-config",
  "quote",
  "syn",
 ]
@@ -2750,12 +2719,6 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
 
-[[package]]
-name = "unindent"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7264e107f553ccae879d21fbea1d6724ac785e8c3bfc762137959b5802826ef3"
-
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
diff --git a/pumpkin-solver-py/Cargo.toml b/pumpkin-solver-py/Cargo.toml
index aae34d8fb..897e4772f 100644
--- a/pumpkin-solver-py/Cargo.toml
+++ b/pumpkin-solver-py/Cargo.toml
@@ -16,7 +16,7 @@ crate-type = ["cdylib"]
 doc = false
 
 [dependencies]
-pyo3 = { version = "0.25.1", features= ["extension-module"] }
+pyo3 = { version = "0.28.3", features= ["extension-module"] }
 pumpkin-solver = { version = "0.3.0", path = "../pumpkin-solver" }
 pumpkin-constraints = { version = "0.3.0", path = "../pumpkin-crates/constraints", features=["clap"] }
 pumpkin-conflict-resolvers = { version = "0.3.0", path = "../pumpkin-crates/conflict-resolvers/"}
diff --git a/pumpkin-solver-py/src/constraints/globals.rs b/pumpkin-solver-py/src/constraints/globals.rs
index f9649c512..75a3a9964 100644
--- a/pumpkin-solver-py/src/constraints/globals.rs
+++ b/pumpkin-solver-py/src/constraints/globals.rs
@@ -7,7 +7,7 @@ use crate::variables::*;
 
 macro_rules! python_constraint {
     ($name:ident : $constraint_func:ident { $($field:ident : $type:ty),+ $(,)? }) => {
-        #[pyclass]
+        #[pyclass(from_py_object)]
         #[derive(Clone)]
         pub(crate) struct $name {
             constraint_tag: Tag,
diff --git a/pumpkin-solver-py/src/model.rs b/pumpkin-solver-py/src/model.rs
index e35b41880..9137b3682 100644
--- a/pumpkin-solver-py/src/model.rs
+++ b/pumpkin-solver-py/src/model.rs
@@ -42,7 +42,7 @@ pub struct Model {
     brancher: PythonBrancher,
 }
 
-#[pyclass]
+#[pyclass(from_py_object)]
 #[derive(Clone, Debug)]
 pub struct Tag(pub ConstraintTag);
 
diff --git a/pumpkin-solver-py/src/optimisation.rs b/pumpkin-solver-py/src/optimisation.rs
index 429caa3d0..956553a69 100644
--- a/pumpkin-solver-py/src/optimisation.rs
+++ b/pumpkin-solver-py/src/optimisation.rs
@@ -2,7 +2,8 @@ use pyo3::prelude::*;
 
 use crate::result::Solution;
 
-#[pyclass]
+#[pyclass(from_py_object)]
+#[derive(Clone)]
 pub enum OptimisationResult {
     /// The problem was solved to optimality, and the solution is an optimal one.
     Optimal(Solution),
@@ -14,14 +15,14 @@ pub enum OptimisationResult {
     Unknown(),
 }
 
-#[pyclass(eq, eq_int)]
+#[pyclass(eq, eq_int, from_py_object)]
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub enum Optimiser {
     LinearSatUnsat,
     LinearUnsatSat,
 }
 
-#[pyclass(eq, eq_int)]
+#[pyclass(eq, eq_int, from_py_object)]
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub enum Direction {
     Minimise,
diff --git a/pumpkin-solver-py/src/result.rs b/pumpkin-solver-py/src/result.rs
index 3df37942a..b13c782a3 100644
--- a/pumpkin-solver-py/src/result.rs
+++ b/pumpkin-solver-py/src/result.rs
@@ -5,16 +5,18 @@ use crate::variables::BoolExpression;
 use crate::variables::IntExpression;
 use crate::variables::Predicate;
 
-#[pyclass]
+#[pyclass(from_py_object)]
 #[allow(clippy::large_enum_variant)]
+#[derive(Clone)]
 pub enum SatisfactionResult {
     Satisfiable(Solution),
     Unsatisfiable(),
     Unknown(),
 }
 
-#[pyclass]
+#[pyclass(from_py_object)]
 #[allow(clippy::large_enum_variant)]
+#[derive(Clone)]
 pub enum SatisfactionUnderAssumptionsResult {
     Satisfiable(Solution),
     UnsatisfiableUnderAssumptions(Vec<Predicate>),
@@ -22,7 +24,7 @@ pub enum SatisfactionUnderAssumptionsResult {
     Unknown(),
 }
 
-#[pyclass]
+#[pyclass(from_py_object)]
 #[derive(Clone)]
 pub struct Solution(pumpkin_solver::core::results::Solution);
 
diff --git a/pumpkin-solver-py/src/variables.rs b/pumpkin-solver-py/src/variables.rs
index 6e9e81527..05b15a4ab 100644
--- a/pumpkin-solver-py/src/variables.rs
+++ b/pumpkin-solver-py/src/variables.rs
@@ -5,7 +5,7 @@ use pumpkin_solver::core::variables::Literal;
 use pumpkin_solver::core::variables::TransformableVariable;
 use pyo3::prelude::*;
 
-#[pyclass(eq, hash, frozen)]
+#[pyclass(eq, hash, frozen, from_py_object)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct IntExpression(pub AffineView<DomainId>);
 
@@ -26,7 +26,7 @@ impl IntExpression {
     }
 }
 
-#[pyclass(eq, hash, frozen)]
+#[pyclass(eq, hash, frozen, from_py_object)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct BoolExpression(pub Literal);
 
@@ -47,7 +47,7 @@ impl From<Literal> for BoolExpression {
     }
 }
 
-#[pyclass(eq, eq_int, hash, frozen)]
+#[pyclass(eq, eq_int, hash, frozen, from_py_object)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum Comparator {
     NotEqual,
@@ -56,7 +56,7 @@ pub enum Comparator {
     GreaterThanOrEqual,
 }
 
-#[pyclass(eq, get_all, hash, frozen)]
+#[pyclass(eq, get_all, hash, frozen, from_py_object)]
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct Predicate {
     pub variable: IntExpression,