diff --git a/src/pyhf/experimental/modifiers.py b/src/pyhf/experimental/modifiers.py
index 42793575f7..167a446d25 100644
--- a/src/pyhf/experimental/modifiers.py
+++ b/src/pyhf/experimental/modifiers.py
@@ -19,13 +19,13 @@ def _allocate_new_param(
     p: dict[str, Sequence[float]]
 ) -> dict[str, str | bool | int | Sequence[float]]:
     return {
-        'paramset_type': 'unconstrained',
-        'n_parameters': 1,
-        'is_shared': True,
-        'inits': p['inits'],
-        'bounds': p['bounds'],
-        'is_scalar': True,
-        'fixed': False,
+        "paramset_type": "unconstrained",
+        "n_parameters": 1,
+        "is_shared": True,
+        "inits": p["inits"],
+        "bounds": p["bounds"],
+        "is_scalar": True,
+        "fixed": False,
     }
 
 
@@ -45,30 +45,30 @@ class _builder(BaseBuilder):
         is_shared = False
 
         def __init__(self, config):
-            self.builder_data = {'funcs': {}}
+            self.builder_data = {"funcs": {}}
             self.config = config
 
         def collect(self, thismod, nom):
             maskval = True if thismod else False
             mask = [maskval] * len(nom)
-            return {'mask': mask}
+            return {"mask": mask}
 
         def append(self, key, channel, sample, thismod, defined_samp):
             self.builder_data.setdefault(key, {}).setdefault(sample, {}).setdefault(
-                'data', {'mask': []}
+                "data", {"mask": []}
             )
             nom = (
-                defined_samp['data']
+                defined_samp["data"]
                 if defined_samp
                 else [0.0] * self.config.channel_nbins[channel]
             )
             moddata = self.collect(thismod, nom)
-            self.builder_data[key][sample]['data']['mask'] += moddata['mask']
+            self.builder_data[key][sample]["data"]["mask"] += moddata["mask"]
             if thismod:
-                if thismod['name'] != funcname:
+                if thismod["name"] != funcname:
                     print(thismod)
-                    self.builder_data['funcs'].setdefault(
-                        thismod['name'], thismod['data']['expr']
+                    self.builder_data["funcs"].setdefault(
+                        thismod["name"], thismod["data"]["expr"]
                     )
                 self.required_parsets = {
                     k: [_allocate_new_param(v)] for k, v in newparams.items()
@@ -85,14 +85,14 @@ def make_applier(
 ) -> BaseApplier:
     class _applier(BaseApplier):
         name = funcname
-        op_code = 'multiplication'
+        op_code = "multiplication"
 
         def __init__(self, modifiers, pdfconfig, builder_data, batch_size=None):
-            self.funcs = [make_func(v, deps) for v in builder_data['funcs'].values()]
+            self.funcs = [make_func(v, deps) for v in builder_data["funcs"].values()]
 
             self.batch_size = batch_size
             pars_for_applier = deps
-            _modnames = [f'{mtype}/{m}' for m, mtype in modifiers]
+            _modnames = [f"{mtype}/{m}" for m, mtype in modifiers]
 
             parfield_shape = (
                 (self.batch_size, pdfconfig.npars)
@@ -103,11 +103,11 @@ def __init__(self, modifiers, pdfconfig, builder_data, batch_size=None):
                 parfield_shape, pdfconfig.par_map, pars_for_applier
             )
             self._custommod_mask = [
-                [[builder_data[modname][s]['data']['mask']] for s in pdfconfig.samples]
+                [[builder_data[modname][s]["data"]["mask"]] for s in pdfconfig.samples]
                 for modname in _modnames
             ]
             self._precompute()
-            events.subscribe('tensorlib_changed')(self._precompute)
+            events.subscribe("tensorlib_changed")(self._precompute)
 
         def _precompute(self):
             tensorlib, _ = get_backend()
@@ -132,15 +132,15 @@ def apply(self, pars):
             tensorlib, _ = get_backend()
             if self.batch_size is None:
                 deps = self.param_viewer.get(pars)
-                print('deps', deps.shape)
+                print("deps", deps.shape)
                 results = tensorlib.astensor([f(deps) for f in self.funcs])
-                results = tensorlib.einsum('msab,m->msab', self.custommod_mask, results)
+                results = tensorlib.einsum("msab,m->msab", self.custommod_mask, results)
             else:
                 deps = self.param_viewer.get(pars)
-                print('deps', deps.shape)
+                print("deps", deps.shape)
                 results = tensorlib.astensor([f(deps) for f in self.funcs])
                 results = tensorlib.einsum(
-                    'msab,ma->msab', self.custommod_mask, results
+                    "msab,ma->msab", self.custommod_mask, results
                 )
             results = tensorlib.where(
                 self.custommod_mask_bool, results, self.custommod_default
diff --git a/tests/test_experimental.py b/tests/test_experimental.py
index 32ca49861c..3f83e52aa0 100644
--- a/tests/test_experimental.py
+++ b/tests/test_experimental.py
@@ -6,38 +6,38 @@ def test_add_custom_modifier(backend):
     tensorlib, _ = backend
 
     new_params = {
-        'm1': {'inits': (1.0,), 'bounds': ((-5.0, 5.0),)},
-        'm2': {'inits': (1.0,), 'bounds': ((-5.0, 5.0),)},
+        "m1": {"inits": (1.0,), "bounds": ((-5.0, 5.0),)},
+        "m2": {"inits": (1.0,), "bounds": ((-5.0, 5.0),)},
     }
 
     expanded_pyhf = pyhf.experimental.modifiers.add_custom_modifier(
-        'customfunc', ['m1', 'm2'], new_params
+        "customfunc", ["m1", "m2"], new_params
     )
     model = pyhf.Model(
         {
-            'channels': [
+            "channels": [
                 {
-                    'name': 'singlechannel',
-                    'samples': [
+                    "name": "singlechannel",
+                    "samples": [
                         {
-                            'name': 'signal',
-                            'data': [10] * 20,
-                            'modifiers': [
+                            "name": "signal",
+                            "data": [10] * 20,
+                            "modifiers": [
                                 {
-                                    'name': 'f2',
-                                    'type': 'customfunc',
-                                    'data': {'expr': 'm1'},
+                                    "name": "f2",
+                                    "type": "customfunc",
+                                    "data": {"expr": "m1"},
                                 },
                             ],
                         },
                         {
-                            'name': 'background',
-                            'data': [100] * 20,
-                            'modifiers': [
+                            "name": "background",
+                            "data": [100] * 20,
+                            "modifiers": [
                                 {
-                                    'name': 'f1',
-                                    'type': 'customfunc',
-                                    'data': {'expr': 'm1+(m2**2)'},
+                                    "name": "f1",
+                                    "type": "customfunc",
+                                    "data": {"expr": "m1+(m2**2)"},
                                 },
                             ],
                         },
@@ -46,7 +46,7 @@ def test_add_custom_modifier(backend):
             ]
         },
         modifier_set=expanded_pyhf,
-        poi_name='m1',
+        poi_name="m1",
         validate=False,
         batch_size=1,
     )