diff --git a/Cargo.toml b/Cargo.toml
index da67ab4a5..e12d6fa2e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,9 +42,9 @@ rand = { version = "0.8", features = ["small_rng"] }
 approx = "0.5"
 getrandom = { version = "0.2", optional = true, features = ["js"] }
 
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-linalg = { version = "0.17", optional = true }
-sprs = { version = "=0.11.2", default-features = false }
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-linalg = { version = "0.18", optional = true }
+sprs = { version = "0.11.4", default-features = false }
 
 thiserror = "2.0"
 
@@ -58,7 +58,7 @@ default-features = false
 features = ["std", "derive"]
 
 [dev-dependencies]
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 linfa-datasets = { path = "datasets", features = [
     "winequality",
     "iris",
diff --git a/algorithms/linfa-bayes/Cargo.toml b/algorithms/linfa-bayes/Cargo.toml
index 2f21d29e3..f48f54eac 100644
--- a/algorithms/linfa-bayes/Cargo.toml
+++ b/algorithms/linfa-bayes/Cargo.toml
@@ -21,8 +21,8 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-stats = "0.6"
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-stats = "0.7"
 thiserror = "2.0"
 
 linfa = { version = "0.8.1", path = "../.." }
diff --git a/algorithms/linfa-clustering/Cargo.toml b/algorithms/linfa-clustering/Cargo.toml
index 4b034789f..6d67308c3 100644
--- a/algorithms/linfa-clustering/Cargo.toml
+++ b/algorithms/linfa-clustering/Cargo.toml
@@ -35,21 +35,21 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["rayon", "approx"] }
+ndarray = { version = "0.17", features = ["rayon", "approx"] }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-linalg = { version = "0.17", optional = true }
-ndarray-rand = "0.15"
-ndarray-stats = "0.6"
+ndarray-linalg = { version = "0.18", optional = true }
+ndarray-rand = "0.16"
+ndarray-stats = "0.7"
 num-traits = "0.2"
-rand_xoshiro = "0.6"
+rand_xoshiro = "0.8"
 space = "0.19"
 thiserror = "2.0"
 linfa = { version = "0.8.1", path = "../.." }
 linfa-nn = { version = "0.8.1", path = "../linfa-nn" }
-noisy_float = "0.2.0"
+noisy_float = "0.2.1"
 
 [dev-dependencies]
-ndarray-npy = { version = "0.9", default-features = false }
+ndarray-npy = { version = "0.10", default-features = false }
 linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
     "generate",
 ] }
diff --git a/algorithms/linfa-elasticnet/Cargo.toml b/algorithms/linfa-elasticnet/Cargo.toml
index dbbf2de68..24e092722 100644
--- a/algorithms/linfa-elasticnet/Cargo.toml
+++ b/algorithms/linfa-elasticnet/Cargo.toml
@@ -29,9 +29,9 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
+ndarray = { version = "0.17", features = ["approx"] }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-linalg = { version = "0.17", optional = true }
+ndarray-linalg = { version = "0.18", optional = true }
 
 num-traits = "0.2"
 approx = "0.5"
@@ -44,5 +44,5 @@ linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
     "diabetes",
     "linnerud",
 ] }
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 rand_xoshiro = "0.6"
diff --git a/algorithms/linfa-ensemble/Cargo.toml b/algorithms/linfa-ensemble/Cargo.toml
index a8e1ffe9c..307918732 100644
--- a/algorithms/linfa-ensemble/Cargo.toml
+++ b/algorithms/linfa-ensemble/Cargo.toml
@@ -27,8 +27,8 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["rayon", "approx"] }
-ndarray-rand = "0.15"
+ndarray = { version = "0.17", features = ["rayon", "approx"] }
+ndarray-rand = "0.16"
 rand = "0.8.5"
 
 linfa = { version = "0.8.1", path = "../.." }
diff --git a/algorithms/linfa-ftrl/Cargo.toml b/algorithms/linfa-ftrl/Cargo.toml
index 8c2f52abf..711455cf8 100644
--- a/algorithms/linfa-ftrl/Cargo.toml
+++ b/algorithms/linfa-ftrl/Cargo.toml
@@ -24,8 +24,8 @@ version = "1.0"
 features = ["derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["serde"] }
-ndarray-rand = "0.15.0"
+ndarray = { version = "0.17", features = ["serde"] }
+ndarray-rand = "0.16.0"
 argmin = { version = "0.11.0", default-features = false }
 argmin-math = { version = "0.5", features = ["ndarray_v0_16-nolinalg"] }
 thiserror = "2.0"
diff --git a/algorithms/linfa-hierarchical/Cargo.toml b/algorithms/linfa-hierarchical/Cargo.toml
index a63a2cec6..16c9c0df4 100644
--- a/algorithms/linfa-hierarchical/Cargo.toml
+++ b/algorithms/linfa-hierarchical/Cargo.toml
@@ -20,7 +20,7 @@ keywords = [
 categories = ["algorithms", "mathematics", "science"]
 
 [dependencies]
-ndarray = { version = "0.16" }
+ndarray = { version = "0.17" }
 kodama = "0.2"
 thiserror = "2"
 
@@ -29,7 +29,7 @@ linfa-kernel = { version = "0.8.1", path = "../linfa-kernel" }
 
 [dev-dependencies]
 rand = "0.8"
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
     "iris",
 ] }
diff --git a/algorithms/linfa-ica/Cargo.toml b/algorithms/linfa-ica/Cargo.toml
index fe377600b..64d4eae11 100644
--- a/algorithms/linfa-ica/Cargo.toml
+++ b/algorithms/linfa-ica/Cargo.toml
@@ -25,11 +25,11 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16" }
+ndarray = { version = "0.17" }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-linalg = { version = "0.17", optional = true }
-ndarray-rand = "0.15"
-ndarray-stats = "0.6"
+ndarray-linalg = { version = "0.18", optional = true }
+ndarray-rand = "0.16"
+ndarray-stats = "0.7"
 num-traits = "0.2"
 rand_xoshiro = "0.6"
 thiserror = "2.0"
@@ -37,7 +37,7 @@ thiserror = "2.0"
 linfa = { version = "0.8.1", path = "../.." }
 
 [dev-dependencies]
-ndarray-npy = { version = "0.9", default-features = false }
+ndarray-npy = { version = "0.10", default-features = false }
 paste = "1.0"
 criterion = "0.5"
 linfa = { version = "0.8.1", path = "../..", features = ["benchmarks"] }
diff --git a/algorithms/linfa-kernel/Cargo.toml b/algorithms/linfa-kernel/Cargo.toml
index 7d038b387..21697ec17 100644
--- a/algorithms/linfa-kernel/Cargo.toml
+++ b/algorithms/linfa-kernel/Cargo.toml
@@ -24,9 +24,9 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = "0.16"
+ndarray = "0.17"
 num-traits = "0.2"
-sprs = { version = "=0.11.2", default-features = false }
+sprs = { version = "0.11.4", default-features = false }
 
 linfa = { version = "0.8.1", path = "../.." }
 linfa-nn = { version = "0.8.1", path = "../linfa-nn" }
diff --git a/algorithms/linfa-lars/Cargo.toml b/algorithms/linfa-lars/Cargo.toml
index 0bd0dcbaa..b6b19d7c4 100644
--- a/algorithms/linfa-lars/Cargo.toml
+++ b/algorithms/linfa-lars/Cargo.toml
@@ -28,9 +28,9 @@ features = ["std", "derive"]
 linfa = { version = "0.8.1", path = "../.." }
 linfa-linalg = { version = "0.2", default-features = false }
 linfa-preprocessing = { version = "0.8.1", path = "../linfa-preprocessing"}
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-linalg = { version = "0.17", optional = true }
-ndarray-stats = "0.6"
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-linalg = { version = "0.18", optional = true }
+ndarray-stats = "0.7"
 thiserror = "2.0"
 
 [dev-dependencies]
@@ -38,5 +38,5 @@ linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
     "diabetes",
 ] }
 approx = "0.5"
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 rand_xoshiro = "0.6"
diff --git a/algorithms/linfa-linear/Cargo.toml b/algorithms/linfa-linear/Cargo.toml
index 99eeb5e50..e60fa50b1 100644
--- a/algorithms/linfa-linear/Cargo.toml
+++ b/algorithms/linfa-linear/Cargo.toml
@@ -29,9 +29,9 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
+ndarray = { version = "0.17", features = ["approx"] }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-linalg = { version = "0.17", optional = true }
+ndarray-linalg = { version = "0.18", optional = true }
 num-traits = "0.2"
 argmin = { version = "0.11.0", default-features = false }
 argmin-math = { version = "0.5", features = ["ndarray_v0_16-nolinalg"] }
diff --git a/algorithms/linfa-logistic/Cargo.toml b/algorithms/linfa-logistic/Cargo.toml
index c771385ac..8efcc9ed7 100644
--- a/algorithms/linfa-logistic/Cargo.toml
+++ b/algorithms/linfa-logistic/Cargo.toml
@@ -23,8 +23,8 @@ optional = true
 version = "1.0"
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-stats = "0.6.0"
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-stats = "0.7.0"
 num-traits = "0.2"
 argmin = { version = "0.11.0", default-features = false }
 argmin-math = { version = "0.5", features = ["ndarray_v0_16-nolinalg"] }
diff --git a/algorithms/linfa-nn/Cargo.toml b/algorithms/linfa-nn/Cargo.toml
index 76b730a56..b07b1da74 100644
--- a/algorithms/linfa-nn/Cargo.toml
+++ b/algorithms/linfa-nn/Cargo.toml
@@ -24,9 +24,9 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-stats = "0.6"
-num-traits = "0.2.0"
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-stats = "0.7"
+num-traits = "0.2.19"
 noisy_float = "0.2.0"
 order-stat = "0.1.3"
 thiserror = "2.0"
@@ -39,7 +39,7 @@ linfa = { version = "0.8.1", path = "../.." }
 approx = "0.5"
 criterion = "0.5"
 rand_xoshiro = "0.6"
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 linfa = { version = "0.8.1", path = "../..", features = ["benchmarks"] }
 
 [[bench]]
diff --git a/algorithms/linfa-pls/Cargo.toml b/algorithms/linfa-pls/Cargo.toml
index 3ec23f59d..c94e95c0b 100644
--- a/algorithms/linfa-pls/Cargo.toml
+++ b/algorithms/linfa-pls/Cargo.toml
@@ -25,11 +25,11 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16" }
+ndarray = { version = "0.17" }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-linalg = { version = "0.17", optional = true }
-ndarray-stats = "0.6"
-ndarray-rand = "0.15"
+ndarray-linalg = { version = "0.18", optional = true }
+ndarray-stats = "0.7"
+ndarray-rand = "0.16"
 num-traits = "0.2"
 paste = "1.0"
 thiserror = "2.0"
diff --git a/algorithms/linfa-preprocessing/Cargo.toml b/algorithms/linfa-preprocessing/Cargo.toml
index 9161d0b41..e456e3a27 100644
--- a/algorithms/linfa-preprocessing/Cargo.toml
+++ b/algorithms/linfa-preprocessing/Cargo.toml
@@ -19,17 +19,17 @@ serde = ["serde_crate", "ndarray/serde", "serde_regex"]
 
 [dependencies]
 linfa = { version = "0.8.1", path = "../.." }
-ndarray = { version = "0.16", features = ["approx"] }
-ndarray-linalg = { version = "0.17", optional = true }
+ndarray = { version = "0.17", features = ["approx"] }
+ndarray-linalg = { version = "0.18", optional = true }
 linfa-linalg = { version = "0.2", default-features = false }
-ndarray-stats = "0.6"
+ndarray-stats = "0.7"
 thiserror = "2.0"
 approx = "0.5"
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 unicode-normalization = "0.1.8"
 regex = "1.4.5"
 encoding = "0.2"
-sprs = { version = "=0.11.2", default-features = false }
+sprs = { version = "0.11.4", default-features = false }
 
 serde_regex = { version = "1.1", optional = true }
 itertools = "0.14.0"
diff --git a/algorithms/linfa-reduction/Cargo.toml b/algorithms/linfa-reduction/Cargo.toml
index 962c87885..760412b53 100644
--- a/algorithms/linfa-reduction/Cargo.toml
+++ b/algorithms/linfa-reduction/Cargo.toml
@@ -34,21 +34,21 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["approx"] }
+ndarray = { version = "0.17", features = ["approx"] }
 linfa-linalg = { version = "0.2" }
-ndarray-linalg = { version = "0.17", optional = true }
-ndarray-rand = "0.15"
+ndarray-linalg = { version = "0.18", optional = true }
+ndarray-rand = "0.16"
 num-traits = "0.2"
 thiserror = "2.0"
 rand = { version = "0.8", features = ["small_rng"] }
 
 linfa = { version = "0.8.1", path = "../.." }
 linfa-kernel = { version = "0.8.1", path = "../linfa-kernel" }
-sprs = { version = "=0.11.2" }
+sprs = { version = "0.11.4" }
 rand_xoshiro = "0.6.0"
 
 [dev-dependencies]
-ndarray-npy = { version = "0.9", default-features = false }
+ndarray-npy = { version = "0.10", default-features = false }
 linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
     "iris",
     "generate",
diff --git a/algorithms/linfa-svm/Cargo.toml b/algorithms/linfa-svm/Cargo.toml
index 58ae69616..872c8bd79 100644
--- a/algorithms/linfa-svm/Cargo.toml
+++ b/algorithms/linfa-svm/Cargo.toml
@@ -24,8 +24,8 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16" }
-ndarray-rand = "0.15"
+ndarray = { version = "0.17" }
+ndarray-rand = "0.16"
 num-traits = "0.2"
 thiserror = "2.0"
 
diff --git a/algorithms/linfa-trees/Cargo.toml b/algorithms/linfa-trees/Cargo.toml
index c14f0c54f..65cebdac6 100644
--- a/algorithms/linfa-trees/Cargo.toml
+++ b/algorithms/linfa-trees/Cargo.toml
@@ -24,8 +24,8 @@ default-features = false
 features = ["std", "derive"]
 
 [dependencies]
-ndarray = { version = "0.16", features = ["rayon", "approx"] }
-ndarray-rand = "0.15"
+ndarray = { version = "0.17", features = ["rayon", "approx"] }
+ndarray-rand = "0.16"
 
 linfa = { version = "0.8.1", path = "../.." }
 
diff --git a/algorithms/linfa-tsne/Cargo.toml b/algorithms/linfa-tsne/Cargo.toml
index 1cf57e622..faf1ed80e 100644
--- a/algorithms/linfa-tsne/Cargo.toml
+++ b/algorithms/linfa-tsne/Cargo.toml
@@ -15,7 +15,7 @@ categories = ["algorithms", "mathematics", "science"]
 
 [dependencies]
 thiserror = "2.0"
-ndarray = { version = "0.16" }
+ndarray = { version = "0.17" }
 bhtsne = { version = "0.5.4", default-features = false }
 
 linfa = { version = "0.8.1", path = "../.." }
@@ -23,7 +23,7 @@ linfa-nn = { version = "0.8.1", path = "../linfa-nn" }
 
 [dev-dependencies]
 rand = "0.8"
-ndarray-rand = "0.15"
+ndarray-rand = "0.16"
 approx = "0.5"
 
 linfa-datasets = { version = "0.8.1", path = "../../datasets", features = [
diff --git a/datasets/Cargo.toml b/datasets/Cargo.toml
index 2cfe0bac0..93d8dd69e 100644
--- a/datasets/Cargo.toml
+++ b/datasets/Cargo.toml
@@ -9,11 +9,11 @@ repository = "https://github.com/rust-ml/linfa"
 
 [dependencies]
 linfa = { version = "0.8.1", path = ".." }
-ndarray = { version = "0.16" }
-ndarray-csv = "=0.5.3"
+ndarray = { version = "0.17" }
+ndarray-csv = "0.5.4"
 csv = "1.1"
 flate2 = "1.0"
-ndarray-rand = { version = "0.15", optional = true }
+ndarray-rand = { version = "0.16", optional = true }
 
 [dev-dependencies]
 approx = "0.5"
diff --git a/src/composing/residual_chain.rs b/src/composing/residual_chain.rs
index 3713703d1..21122673e 100644
--- a/src/composing/residual_chain.rs
+++ b/src/composing/residual_chain.rs
@@ -118,7 +118,6 @@
 //! ```
 
 use crate::dataset::{AsTargets, DatasetBase, Records};
-use crate::param_guard::ParamGuard;
 use crate::traits::{Fit, Predict, PredictInplace};
 use crate::Float;
 use ndarray::{Array1, Array2, ArrayBase, Data, Ix1, Ix2, RawDataClone};
@@ -263,45 +262,6 @@ impl<B> Stagewise for B {
     }
 }
 
-impl<F1, F2, F: Float, D: Data<Elem = F> + RawDataClone, T, E1, E2>
-    Fit<Arr2<D>, T, ResidualChainError<E1, E2>> for ResidualChain<F1, F2, F>
-where
-    Arr2<D>: Records,
-    F1: Fit<Arr2<D>, T, E1>,
-    for<'a> F1::Object: Predict<&'a Arr2<D>, Array1<F>>,
-    F2: Fit<Arr2<D>, Array1<F>, E2>,
-    T: AsTargets<Elem = F, Ix = Ix1>,
-    E1: std::error::Error + From<crate::error::Error>,
-    E2: std::error::Error + From<crate::error::Error>,
-{
-    type Object = ResidualChain<F1::Object, F2::Object, F>;
-
-    fn fit(
-        &self,
-        dataset: &DatasetBase<Arr2<D>, T>,
-    ) -> Result<Self::Object, ResidualChainError<E1, E2>> {
-        let base = self.base.fit(dataset).map_err(ResidualChainError::Base)?;
-
-        let y_pred = base.predict(dataset.records());
-        let residuals = &dataset.targets().as_targets() - &y_pred;
-
-        let residual_dataset = DatasetBase::new(dataset.records().clone(), residuals);
-        let corrector_model = self
-            .corrector
-            .model
-            .fit(&residual_dataset)
-            .map_err(ResidualChainError::Corrector)?;
-
-        Ok(ResidualChain {
-            base,
-            corrector: Shrunk {
-                model: corrector_model,
-                shrinkage: self.corrector.shrinkage,
-            },
-        })
-    }
-}
-
 impl<R1, R2, F: Float, D: Data<Elem = F>> PredictInplace<Arr2<D>, Array1<F>>
     for ResidualChain<R1, R2, F>
 where
@@ -349,8 +309,8 @@ impl<M, F: Float> Shrunk<M, F> {
     pub fn shrinkage(&self) -> F {
         self.shrinkage
     }
-    /// Set the shrinkage factor. Validation happens when the containing
-    /// [`ResidualChainParams`] is checked via [`ParamGuard`].
+    /// Set the shrinkage factor. Validation (shrinkage ∈ (0, 1]) happens
+    /// at `.fit()` time on the containing [`ResidualChainParams`].
     pub fn with_shrinkage(mut self, shrinkage: F) -> Self {
         self.shrinkage = shrinkage;
         self
@@ -359,11 +319,10 @@ impl<M, F: Float> Shrunk<M, F> {
 
 /// Unvalidated [`ResidualChain`] parameters returned by [`Stagewise::chain_shrunk`].
 ///
-/// Call `.fit()` to validate and fit in one step — the [`ParamGuard`] blanket
-/// impl runs `check_ref` first, which verifies that the outermost corrector's
-/// shrinkage factor is in (0, 1]. Inner chains validate lazily when their own
-/// `.fit()` is called. You can also call `.check()` / `.check_unwrap()` to
-/// validate explicitly.
+/// Call `.fit()` to validate and fit in one step — `.fit()` validates that the
+/// outermost corrector's shrinkage factor is in (0, 1] before fitting. Inner
+/// chains validate lazily when their own `.fit()` is called. You can also call
+/// `.check()` / `.check_unwrap()` to validate the shrinkage factor explicitly.
 ///
 /// To set an explicit shrinkage factor on the corrector use
 /// [`Shrunk::with_shrinkage`]:
@@ -393,11 +352,11 @@ impl<M, F: Float> Shrunk<M, F> {
 #[derive(Debug, Clone, Copy)]
 pub struct ResidualChainParams<B, C, F: Float>(ResidualChain<B, C, F>);
 
-impl<B, C, F: Float> ParamGuard for ResidualChainParams<B, C, F> {
-    type Checked = ResidualChain<B, C, F>;
-    type Error = crate::Error;
-
-    fn check_ref(&self) -> Result<&ResidualChain<B, C, F>, crate::Error> {
+impl<B, C, F: Float> ResidualChainParams<B, C, F> {
+    /// Validate the shrinkage factor and return a reference to the inner
+    /// [`ResidualChain`]. Returns an error if the shrinkage factor is not
+    /// in (0, 1].
+    pub fn check_ref(&self) -> Result<&ResidualChain<B, C, F>, crate::Error> {
         let v = self.0.corrector.shrinkage;
         if v > F::zero() && v <= F::one() {
             Ok(&self.0)
@@ -408,10 +367,65 @@ impl<B, C, F: Float> ParamGuard for ResidualChainParams<B, C, F> {
         }
     }
 
-    fn check(self) -> Result<ResidualChain<B, C, F>, crate::Error> {
+    /// Validate the shrinkage factor and return the inner [`ResidualChain`].
+    /// Returns an error if the shrinkage factor is not in (0, 1].
+    pub fn check(self) -> Result<ResidualChain<B, C, F>, crate::Error> {
         self.check_ref()?;
         Ok(self.0)
     }
+
+    /// Validate the shrinkage factor, panicking on error.
+    pub fn check_unwrap(self) -> ResidualChain<B, C, F> {
+        self.check().unwrap()
+    }
+}
+
+impl<F1, M1, F2, M2, F: Float, D: Data<Elem = F> + RawDataClone, T, E1, E2>
+    Fit<Arr2<D>, T, ResidualChainError<E1, E2>> for ResidualChainParams<F1, F2, F>
+where
+    Arr2<D>: Records,
+    F1: Fit<Arr2<D>, T, E1, Object = M1>,
+    for<'a> M1: Predict<&'a Arr2<D>, Array1<F>>,
+    F2: Fit<Arr2<D>, Array1<F>, E2, Object = M2>,
+    T: AsTargets<Elem = F, Ix = Ix1>,
+    E1: std::error::Error + From<crate::error::Error>,
+    E2: std::error::Error + From<crate::error::Error>,
+{
+    type Object = ResidualChain<M1, M2, F>;
+
+    fn fit(
+        &self,
+        dataset: &DatasetBase<Arr2<D>, T>,
+    ) -> Result<Self::Object, ResidualChainError<E1, E2>> {
+        // Validate shrinkage factor before fitting.
+        let v = self.0.corrector.shrinkage;
+        if !(v > F::zero() && v <= F::one()) {
+            return Err(ResidualChainError::BaseCrate(crate::Error::Parameters(
+                format!("shrinkage must be in (0, 1], got {v}"),
+            )));
+        }
+
+        let base = self.0.base.fit(dataset).map_err(ResidualChainError::Base)?;
+
+        let y_pred = base.predict(dataset.records());
+        let residuals = (&dataset.targets().as_targets() - &y_pred).to_owned();
+
+        let residual_dataset = DatasetBase::new(dataset.records().clone(), residuals);
+        let corrector_model = self
+            .0
+            .corrector
+            .model
+            .fit(&residual_dataset)
+            .map_err(ResidualChainError::Corrector)?;
+
+        Ok(ResidualChain {
+            base,
+            corrector: Shrunk {
+                model: corrector_model,
+                shrinkage: self.0.corrector.shrinkage,
+            },
+        })
+    }
 }
 
 #[cfg(test)]