diff --git a/doorcontrol/hid/DoorController.py b/doorcontrol/hid/DoorController.py
index da4421d..d40738c 100644
--- a/doorcontrol/hid/DoorController.py
+++ b/doorcontrol/hid/DoorController.py
@@ -152,7 +152,7 @@ class DoorController:
         )
         return self.doXMLRequest(el)
 
-    def get_records(self, req, count, params={}, stopFunction=None):
+    def get_records(self, req, count, params=None, stopFunction=None):
         recordCount = 0
         moreRecords = True
 
@@ -172,7 +172,7 @@ class DoorController:
                             "recordOffset": str(
                                 recordCount - 1 if recordCount > 0 else 0
                             ),
-                            **params,
+                            **(params or {}),
                         }
                     )
                 )
diff --git a/doorcontrol/hid/tests/test_DoorController.py b/doorcontrol/hid/tests/test_DoorController.py
index 8059780..c7aa6b9 100644
--- a/doorcontrol/hid/tests/test_DoorController.py
+++ b/doorcontrol/hid/tests/test_DoorController.py
@@ -15,7 +15,7 @@ def assert_elements_equal(e1: Element, e2: Element) -> None:
     assert e1.attrib == e2.attrib
     assert len(e1) == len(e2)
 
-    for c1, c2 in zip(e1, e2):
+    for c1, c2 in zip(e1, e2, strict=True):
         assert_elements_equal(c1, c2)
 
 
diff --git a/doorcontrol/tasks/update_doors.py b/doorcontrol/tasks/update_doors.py
index 3cdc18c..3c155d0 100644
--- a/doorcontrol/tasks/update_doors.py
+++ b/doorcontrol/tasks/update_doors.py
@@ -136,7 +136,7 @@ class DoorMember:
         self,
         existing_door_credentials: set[Credential],
         all_members: list["DoorMember"],
-        old_credentials: set[Credential] = set(),
+        old_credentials: set[Credential],
     ):
         # cardholderID should be set on a member before this is called
         assert self.cardholderID is not None
@@ -240,7 +240,7 @@ def update_door(door: Door, dry_run: bool = False):
                 ]
 
                 member.update_attribs()
-                member.update_credentials(existing_door_credentials, members)
+                member.update_credentials(existing_door_credentials, members, set())
                 member.update_schedules()
 
         # cardholder exists, compare contents
diff --git a/membershipworks/models.py b/membershipworks/models.py
index 0e8b456..80941fc 100644
--- a/membershipworks/models.py
+++ b/membershipworks/models.py
@@ -590,7 +590,7 @@ class EventExt(Event):
                 self.materials_fee_included_in_price is not None
                 or self.materials_fee == 0
             )
-            and getattr(self, "total_due_to_instructor") is not None
+            and self.total_due_to_instructor is not None
         )
 
 
diff --git a/membershipworks/tasks/scrape.py b/membershipworks/tasks/scrape.py
index 3fa72d5..f08505f 100644
--- a/membershipworks/tasks/scrape.py
+++ b/membershipworks/tasks/scrape.py
@@ -81,7 +81,9 @@ def scrape_transactions(membershipworks: MembershipWorks):
     transactions_csv = membershipworks.get_transactions(start_date, now)
     transactions_json = membershipworks.get_transactions(start_date, now, json=True)
     # this is terrible, but as long as the dates are the same, should be fiiiine
-    transactions = [{**j, **v} for j, v in zip(transactions_csv, transactions_json)]
+    transactions = [
+        {**j, **v} for j, v in zip(transactions_csv, transactions_json, strict=True)
+    ]
     assert all(
         t["Account ID"] == t.get("uid", "") and t["Payment ID"] == t.get("sid", "")
         for t in transactions
diff --git a/pyproject.toml b/pyproject.toml
index 23efa8b..662c5af 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -83,6 +83,7 @@ select = [
   "TCH",
   "PTH",
   "FURB",
+  "B",
 ]
 ignore = ["ISC001"]