diff --git a/tests/fixtures/bruker.json b/tests/fixtures/bruker.json
index 41f700a515a3762722ff5f596fb2e66e6033f048..d8164bb079a2a57d01c2bf30cce36a6ea60939b4 100644
--- a/tests/fixtures/bruker.json
+++ b/tests/fixtures/bruker.json
@@ -20,7 +20,7 @@
         "passwordUpdated": "2019-03-14T18:50:10.827",
         "unit4Id": ""
     },
-    "roleAndCompany": [
+    "rolesAndCompanies": [
         {
             "roleId": "D-ANMODER",
             "companyId": "72",
diff --git a/tests/test_client.py b/tests/test_client.py
index 6743240958996a455c41ec3413132f77589a417d..c00ecb9144573f6726ede41018f3162ce4b774ff 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -472,6 +472,7 @@ def test_get_bilagstype(client, requests_mock, bilagstype_data):
     expected = Bilagstype.from_dict(bilagstype_data[0])
     assert expected == received
 
+
 def test_get_ressurs(client, base_url, requests_mock, ressurs_data):
     company_id = "72"
     ressurs_id = "99999"
diff --git a/tests/test_model.py b/tests/test_model.py
index 4255774cf53dcff41a1d7d45ed9709e92c5a0b81..f5f31277b5ee03331b18013c1fb4206b8fdc5dcd 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -98,6 +98,7 @@ def test_bilagstype(bilagstype_data):
     assert model.updated_at == bilagstype_data[0]["updatedAt"]
     assert model.updated_by == bilagstype_data[0]["updatedBy"]
 
+
 def test_ressurs(ressurs_data):
     model = Ressurs(**ressurs_data[0])
     assert model.age == ressurs_data[0]["age"]
diff --git a/tests/test_urls.py b/tests/test_urls.py
index ab39f0d396035d4227831d9477bc26d8ffe6415c..41a0e7eeca1e5cd842165fd3d9a824d1f4827284 100644
--- a/tests/test_urls.py
+++ b/tests/test_urls.py
@@ -158,6 +158,7 @@ def test_bilagstyper_url_no_override_wo_trailing_slash(config_no_overrides):
     url = client.urls.get_bilagstype("72", "TT")
     assert url == "https://example.com/base/bilagstyper/v1/72/TT"
 
+
 def test_ressurser_url_no_override_w_trailing_slash(config_no_overrides):
     config_no_overrides["rest"]["base_url"] += "base/"  # trailing slash
     client = get_client(**config_no_overrides)
diff --git a/ubw_client/client.py b/ubw_client/client.py
index a220c090db91222b3201dc08b5827628eaa77e4d..237a2236b26024a7e0cf0cfcbb2b5d6b93f59647 100644
--- a/ubw_client/client.py
+++ b/ubw_client/client.py
@@ -545,30 +545,38 @@ class UBWClient:
         r = self.get(url, headers=headers)
         return [models.Arbeidsordre.from_dict(x) for x in r]
 
-    # TODO: Extend get_arbeidsordrer to support the same partial model as the following function
-    def get_partial_arbeidsordrer(self, company_id: str) -> typing.List[models.PartialArbeidsordre]:
+    # TODO: Extend get_arbeidsordrer to support the same partial model as the following
+    #  function
+    def get_partial_arbeidsordrer(
+        self, company_id: str
+    ) -> typing.List[models.PartialArbeidsordre]:
         url = self.urls.get_arbeidsordre(company_id)
         headers = self.config.rest.endpoints.begreper.headers
-        r = self.get(url,
-                     headers=headers,
-                     params={
-                        'select': ','.join(
-                            ['companyId',
-                             'workOrderId',
-                             'dateFrom',
-                             'dateTo',
-                             'periodFrom',
-                             'periodTo',
-                             'status',
-                             'projectId',
-                             'workOrderName',
-                             'costCentre',
-                             'projectManagerId',
-                             'category1',
-                             'lastUpdated(updatedAt,updatedBy)'])})
+        r = self.get(
+            url,
+            headers=headers,
+            params={
+                "select": ",".join(
+                    [
+                        "companyId",
+                        "workOrderId",
+                        "dateFrom",
+                        "dateTo",
+                        "periodFrom",
+                        "periodTo",
+                        "status",
+                        "projectId",
+                        "workOrderName",
+                        "costCentre",
+                        "projectManagerId",
+                        "category1",
+                        "lastUpdated(updatedAt,updatedBy)",
+                    ]
+                )
+            },
+        )
         return [models.PartialArbeidsordre.from_dict(x) for x in r]
 
-
     def get_perioder(
         self,
         company_id: str,
diff --git a/ubw_client/models.py b/ubw_client/models.py
index 9f444d110b951ae6f002aa22218439ef8da31501..791d12274b9d821b2a179402fdde70d868cd06e6 100644
--- a/ubw_client/models.py
+++ b/ubw_client/models.py
@@ -155,6 +155,7 @@ class Transaction(BaseModel):
     voucher_no: int
     voucher_type: str
     ex_ref: typing.Optional[str]
+    ext_inv_ref: typing.Optional[str]
     ext_arch_ref_col: typing.Optional[str]
 
     class Config:
@@ -606,15 +607,6 @@ class Usage(BaseModel):
         allow_population_by_field_name = True
 
 
-def bruker_model_to_lower_camel(s: str) -> str:
-    """Alias generator to avoid breaking PEP8"""
-    if s == 'role_and_company':
-        return 'rolesAndCompanies'
-    else:
-        first, *others = s.split("_")
-        return "".join([first.lower(), *map(str.capitalize, others)])
-
-
 class Bruker(BaseModel):
     user_id: str
     user_name: str
@@ -625,10 +617,12 @@ class Bruker(BaseModel):
     language_code: typing.Optional[str]
     usage: typing.Optional[Usage]
     contact_points: typing.Optional[typing.List[ContactPoint]]
-    role_and_company: typing.Optional[typing.List[RoleAndCompany]]
+    role_and_company: typing.Optional[typing.List[RoleAndCompany]] = pydantic.Field(
+        alias="rolesAndCompanies"
+    )
 
     class Config:
-        alias_generator = bruker_model_to_lower_camel
+        alias_generator = to_lower_camel
         allow_population_by_field_name = True