diff --git a/lshmm/fb_haploid.py b/lshmm/fb_haploid.py
index 89cab51..8f7b311 100644
--- a/lshmm/fb_haploid.py
+++ b/lshmm/fb_haploid.py
@@ -8,7 +8,7 @@
 
 @jit.numba_njit
 def forwards_ls_hap(
-    n, m, H, s, e, r, norm=True, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, emission_func, *, norm=True,
 ):
     """
     A matrix-based implementation using Numpy.
@@ -82,7 +82,7 @@ def forwards_ls_hap(
 
 @jit.numba_njit
 def backwards_ls_hap(
-    n, m, H, s, e, c, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, c, r, *, emission_func,
 ):
     """
     A matrix-based implementation using Numpy.
diff --git a/lshmm/vit_haploid.py b/lshmm/vit_haploid.py
index f608edb..b772324 100644
--- a/lshmm/vit_haploid.py
+++ b/lshmm/vit_haploid.py
@@ -8,7 +8,7 @@
 
 @jit.numba_njit
 def viterbi_naive_init(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """Initialise a naive implementation."""
     V = np.zeros((m, n))
@@ -30,7 +30,7 @@ def viterbi_naive_init(
 
 @jit.numba_njit
 def viterbi_init(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """Initialise a naive, but more memory efficient, implementation."""
     V_prev = np.zeros(n)
@@ -53,7 +53,7 @@ def viterbi_init(
 
 @jit.numba_njit
 def forwards_viterbi_hap_naive(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """A naive implementation of the forward pass."""
     V, P, r_n = viterbi_naive_init(n, m, H, s, e, r, emission_func)
@@ -83,7 +83,7 @@ def forwards_viterbi_hap_naive(
 
 @jit.numba_njit
 def forwards_viterbi_hap_naive_vec(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """A naive matrix-based implementation of the forward pass."""
     V, P, r_n = viterbi_naive_init(n, m, H, s, e, r, emission_func)
@@ -110,7 +110,7 @@ def forwards_viterbi_hap_naive_vec(
 
 @jit.numba_njit
 def forwards_viterbi_hap_naive_low_mem(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """A naive implementation of the forward pass with reduced memory."""
     V, V_prev, P, r_n = viterbi_init(n, m, H, s, e, r, emission_func)
@@ -141,7 +141,7 @@ def forwards_viterbi_hap_naive_low_mem(
 
 @jit.numba_njit
 def forwards_viterbi_hap_naive_low_mem_rescaling(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """A naive implementation of the forward pass with reduced memory and rescaling."""
     V, V_prev, P, r_n = viterbi_init(n, m, H, s, e, r, emission_func)
@@ -175,7 +175,7 @@ def forwards_viterbi_hap_naive_low_mem_rescaling(
 
 @jit.numba_njit
 def forwards_viterbi_hap_low_mem_rescaling(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """An implementation with reduced memory that exploits the Markov structure."""
     V, V_prev, P, r_n = viterbi_init(n, m, H, s, e, r, emission_func)
@@ -208,7 +208,7 @@ def forwards_viterbi_hap_low_mem_rescaling(
 
 @jit.numba_njit
 def forwards_viterbi_hap_lower_mem_rescaling(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """
     An implementation with even smaller memory footprint
@@ -255,7 +255,7 @@ def forwards_viterbi_hap_lower_mem_rescaling(
 
 @jit.numba_njit
 def forwards_viterbi_hap_lower_mem_rescaling_no_pointer(
-    n, m, H, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, s, e, r, *, emission_func,
 ):
     """
     An implementation with even smaller memory footprint and rescaling
@@ -339,7 +339,7 @@ def backwards_viterbi_hap_no_pointer(m, V_argmaxes, recombs):
 
 @jit.numba_njit
 def path_ll_hap(
-    n, m, H, path, s, e, r, *, emission_func=core.get_emission_probability_haploid
+    n, m, H, path, s, e, r, *, emission_func,
 ):
     """
     Evaluate the log-likelihood of a path through a reference panel resulting in a query.
diff --git a/tests/test_api_fb_haploid.py b/tests/test_api_fb_haploid.py
index 7238283..1cf9656 100644
--- a/tests/test_api_fb_haploid.py
+++ b/tests/test_api_fb_haploid.py
@@ -16,7 +16,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
             include_ancestors=include_ancestors,
             include_extreme_rates=True,
         ):
-            num_alleles = core.get_num_alleles(H_vs, s)
+            emission_func = core.get_emission_probability_haploid
             F_vs, c_vs, ll_vs = fbh.forwards_ls_hap(
                 n=n,
                 m=m,
@@ -24,6 +24,8 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
                 s=s,
                 e=e_vs,
                 r=r,
+                emission_func=emission_func,
+                norm=True,
             )
             B_vs = fbh.backwards_ls_hap(
                 n=n,
@@ -33,6 +35,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
                 e=e_vs,
                 c=c_vs,
                 r=r,
+                emission_func=emission_func,
             )
             F, c, ll = ls.forwards(
                 reference_panel=H_vs,
diff --git a/tests/test_api_fb_haploid_multi.py b/tests/test_api_fb_haploid_multi.py
index a90f57a..77b1b6d 100644
--- a/tests/test_api_fb_haploid_multi.py
+++ b/tests/test_api_fb_haploid_multi.py
@@ -16,6 +16,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
             include_ancestors=include_ancestors,
             include_extreme_rates=True,
         ):
+            emission_func = core.get_emission_probability_haploid
             F_vs, c_vs, ll_vs = fbh.forwards_ls_hap(
                 n=n,
                 m=m,
@@ -23,6 +24,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
                 s=s,
                 e=e_vs,
                 r=r,
+                emission_func=emission_func,
             )
             B_vs = fbh.backwards_ls_hap(
                 n=n,
@@ -32,6 +34,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
                 e=e_vs,
                 c=c_vs,
                 r=r,
+                emission_func=emission_func,
             )
             F, c, ll = ls.forwards(
                 reference_panel=H_vs,
diff --git a/tests/test_api_vit_haploid_multi.py b/tests/test_api_vit_haploid_multi.py
index 5020171..d7dce8a 100644
--- a/tests/test_api_vit_haploid_multi.py
+++ b/tests/test_api_vit_haploid_multi.py
@@ -16,6 +16,7 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
             include_ancestors=include_ancestors,
             include_extreme_rates=True,
         ):
+            emission_func = core.get_emission_probability_haploid
             V_vs, P_vs, ll_vs = vh.forwards_viterbi_hap_lower_mem_rescaling(
                 n=n,
                 m=m,
@@ -23,9 +24,19 @@ def verify(self, ts, scale_mutation_rate, include_ancestors):
                 s=s,
                 e=e_vs,
                 r=r,
+                emission_func=emission_func,
             )
             path_vs = vh.backwards_viterbi_hap(m=m, V_last=V_vs, P=P_vs)
-            path_ll_hap = vh.path_ll_hap(n, m, H_vs, path_vs, s, e_vs, r)
+            path_ll_hap = 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,
+            )
             path, ll = ls.viterbi(
                 reference_panel=H_vs,
                 query=s,
@@ -44,11 +55,7 @@ def test_ts_multiallelic_n10_no_recomb(
         self, scale_mutation_rate, include_ancestors
     ):
         ts = self.get_ts_multiallelic_n10_no_recomb()
-        self.verify(
-            ts,
-            scale_mutation_rate=scale_mutation_rate,
-            include_ancestors=include_ancestors,
-        )
+        self.verify(ts, scale_mutation_rate, include_ancestors)
 
     @pytest.mark.parametrize("num_samples", [6, 8, 16])
     @pytest.mark.parametrize("scale_mutation_rate", [True, False])
diff --git a/tests/test_nontree_fb_haploid.py b/tests/test_nontree_fb_haploid.py
index 7f76a0f..c8f277e 100644
--- a/tests/test_nontree_fb_haploid.py
+++ b/tests/test_nontree_fb_haploid.py
@@ -10,20 +10,22 @@
 
 class TestNonTreeForwardBackwardHaploid(lsbase.ForwardBackwardAlgorithmBase):
     def verify(self, ts, scale_mutation_rate, include_ancestors):
+        ploidy = 1
         for n, m, H_vs, s, e_vs, r, _ in self.get_examples_pars(
             ts,
-            ploidy=1,
+            ploidy=ploidy,
             scale_mutation_rate=scale_mutation_rate,
             include_ancestors=include_ancestors,
             include_extreme_rates=True,
         ):
-            F_vs, c_vs, ll_vs = fbh.forwards_ls_hap(n, m, H_vs, s, e_vs, r, norm=False)
-            B_vs = fbh.backwards_ls_hap(n, m, H_vs, s, e_vs, c_vs, r)
+            emission_func = core.get_emission_probability_haploid
+            F_vs, c_vs, ll_vs = fbh.forwards_ls_hap(n, m, H_vs, s, e_vs, r, emission_func, norm=False)
+            B_vs = fbh.backwards_ls_hap(n, m, H_vs, s, e_vs, c_vs, r, emission_func)
             self.assertAllClose(np.log10(np.sum(F_vs * B_vs, 1)), ll_vs * np.ones(m))
             F_tmp, c_tmp, ll_tmp = fbh.forwards_ls_hap(
-                n, m, H_vs, s, e_vs, r, norm=True
+                n, m, H_vs, s, e_vs, r, emission_func, norm=True,
             )
-            B_tmp = fbh.backwards_ls_hap(n, m, H_vs, s, e_vs, c_tmp, r)
+            B_tmp = fbh.backwards_ls_hap(n, m, H_vs, s, e_vs, c_tmp, r, emission_func)
             self.assertAllClose(np.sum(F_tmp * B_tmp, 1), np.ones(m))
             self.assertAllClose(ll_vs, ll_tmp)
 
diff --git a/tests/test_nontree_vit_haploid.py b/tests/test_nontree_vit_haploid.py
index 93bd7a5..1b61887 100644
--- a/tests/test_nontree_vit_haploid.py
+++ b/tests/test_nontree_vit_haploid.py
@@ -10,9 +10,10 @@
 
 class TestNonTreeViterbiHaploid(lsbase.ViterbiAlgorithmBase):
     def verify(self, ts, scale_mutation_rate, include_ancestors):
+        ploidy = 1
         for n, m, H_vs, s, e_vs, r, _ in self.get_examples_pars(
             ts,
-            ploidy=1,
+            ploidy=ploidy,
             scale_mutation_rate=scale_mutation_rate,
             include_ancestors=include_ancestors,
             include_extreme_rates=True,