diff --git a/tests/test_nontree_vit_haploid_fixed_switches.py b/tests/test_nontree_vit_haploid_fixed_switches.py
new file mode 100644
index 0000000..2753875
--- /dev/null
+++ b/tests/test_nontree_vit_haploid_fixed_switches.py
@@ -0,0 +1,294 @@
+import pytest
+
+import numpy as np
+import numba as nb
+
+from . import lsbase
+import lshmm.core as core
+import lshmm.vit_haploid as vh
+
+
+class TestNonTreeViterbiHaploidFixedSwitches(lsbase.ViterbiAlgorithmBase):
+    def get_examples_pars(self, scale_mutation_rate):
+        # Set ref. panel and query.
+        # fmt: off
+        H = np.array(
+            [
+                [0, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+                [1, 1, 1, 1, 1, 1, 1, 1, 1, 1,],
+            ],
+            dtype=np.int8,
+        ).T
+        query = np.array(
+            [
+                [0, 0, 1, 1, 1, 1, 1, 1, 0, 0, ],
+            ],
+            dtype=np.int8,
+        )
+        # fmt: on
+
+        n = H.shape[1]  # Number of ref. haps
+        m = H.shape[0]  # Number of sites
+
+        # Set constant mutation probability.
+        mu = np.zeros(m, dtype=np.float64) + 1e-4
+
+        # Set emission prob. matrix.
+        num_alleles = core.get_num_alleles(H, query)
+        e = core.get_emission_matrix_haploid(
+            mu=mu,
+            num_sites=m,
+            num_alleles=num_alleles,
+            scale_mutation_rate=scale_mutation_rate,
+        )
+
+        # Set recombination probabilities for different sets of fixed switches.
+        recomb_rates_no_switch = np.zeros(m, dtype=np.float64)
+        recomb_rates_nonzero_start = np.zeros_like(recomb_rates_no_switch)
+        recomb_rates_nonzero_start[0] = 1e-2
+        recomb_rates_nonzero_mid = np.zeros_like(recomb_rates_no_switch)
+        recomb_rates_nonzero_mid[2] = 1e-2
+        recomb_rates_nonzero_end = np.zeros_like(recomb_rates_no_switch)
+        recomb_rates_nonzero_end[-1] = 1e-2
+        recomb_rates_two_switches = np.zeros_like(recomb_rates_no_switch)
+        recomb_rates_two_switches[2] = 1e-2
+        recomb_rates_two_switches[8] = 1e-2
+        recomb_rates_arr = [
+            recomb_rates_no_switch,
+            recomb_rates_nonzero_start,
+            recomb_rates_nonzero_mid,
+            recomb_rates_nonzero_end,
+            recomb_rates_two_switches,
+        ]
+
+        # Expected paths
+        # fmt: off
+        path_no_switch = np.array(
+            [1, 1, 1, 1, 1, 1, 1, 1, 1, 1,],
+            dtype=np.int8,
+        )
+        path_nonzero_start = np.array(
+            [1, 1, 1, 1, 1, 1, 1, 1, 1, 1,],
+            dtype=np.int8,
+        )
+        path_nonzero_mid = np.array(
+            [0, 0, 1, 1, 1, 1, 1, 1, 1, 1,],
+            dtype=np.int8,
+        )
+        path_nonzero_end = np.array(
+            [1, 1, 1, 1, 1, 1, 1, 1, 1, 0,],
+            dtype=np.int8,
+        )
+        path_two_switches = np.array(
+            [0, 0, 1, 1, 1, 1, 1, 1, 0, 0,],
+            dtype=np.int8,
+        )
+        # fmt: on
+        paths_arr = [
+            path_no_switch,
+            path_nonzero_start,
+            path_nonzero_mid,
+            path_nonzero_end,
+            path_two_switches,
+        ]
+
+        for r, path in zip(recomb_rates_arr, paths_arr):
+            yield n, m, H, query, e, r, path
+
+    def verify(self, scale_mutation_rate):
+        for n, m, H_vs, s, e_vs, r, path in self.get_examples_pars(scale_mutation_rate):
+            emission_func = core.get_emission_probability_haploid
+
+            # Implementation: naive
+            V_vs, P_vs, ll_vs = vh.forwards_viterbi_hap_naive(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_vs = vh.backwards_viterbi_hap(
+                m=m,
+                V_last=V_vs[m - 1, :],
+                P=P_vs,
+            )
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_vs, path)
+            self.assertAllClose(ll_vs, ll_check)
+
+            # Implementation: naive, vectorised
+            V_tmp, P_tmp, ll_tmp = vh.forwards_viterbi_hap_naive_vec(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap(
+                m=m,
+                V_last=V_tmp[m - 1, :],
+                P=P_tmp,
+            )
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+            # Implementation: naive, low memory footprint
+            V_tmp, P_tmp, ll_tmp = vh.forwards_viterbi_hap_naive_low_mem(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap(m=m, V_last=V_tmp, P=P_tmp)
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+            # Implementation: naive, low memory footprint, rescaling
+            V_tmp, P_tmp, ll_tmp = vh.forwards_viterbi_hap_naive_low_mem_rescaling(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap(m=m, V_last=V_tmp, P=P_tmp)
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+            # Implementation: low memory footprint, rescaling
+            V_tmp, P_tmp, ll_tmp = vh.forwards_viterbi_hap_low_mem_rescaling(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap(m=m, V_last=V_tmp, P=P_tmp)
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+            # Implementation: even lower memory footprint, rescaling
+            V_tmp, P_tmp, ll_tmp = vh.forwards_viterbi_hap_lower_mem_rescaling(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap(m=m, V_last=V_tmp, P=P_tmp)
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+            (
+                V_tmp,
+                V_argmaxes_tmp,
+                recombs,
+                ll_tmp,
+            ) = vh.forwards_viterbi_hap_lower_mem_rescaling_no_pointer(
+                n=n,
+                m=m,
+                H=H_vs,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            path_tmp = vh.backwards_viterbi_hap_no_pointer(
+                m=m,
+                V_argmaxes=V_argmaxes_tmp,
+                recombs=nb.typed.List(recombs),
+            )
+            ll_check = vh.path_ll_hap(
+                n=n,
+                m=m,
+                H=H_vs,
+                path=path_tmp,
+                s=s,
+                e=e_vs,
+                r=r,
+                emission_func=emission_func,
+            )
+            np.testing.assert_equal(path_tmp, path)
+            self.assertAllClose(ll_tmp, ll_check)
+            self.assertAllClose(ll_vs, ll_tmp)
+
+    @pytest.mark.parametrize("scale_mutation_rate", [True, False])
+    def test_fixed_switches(self, scale_mutation_rate):
+        self.verify(scale_mutation_rate)