diff --git a/analytics/views/support.py b/analytics/views/support.py
index f4fc22f6d2..4c786301dc 100644
--- a/analytics/views/support.py
+++ b/analytics/views/support.py
@@ -142,11 +142,11 @@ def support(
         default=None, str_validator=check_string_in(VALID_BILLING_METHODS)
     ),
     sponsorship_pending: Optional[bool] = REQ(default=None, json_validator=check_bool),
-    approve_sponsorship: Optional[bool] = REQ(default=None, json_validator=check_bool),
+    approve_sponsorship: bool = REQ(default=False, json_validator=check_bool),
     downgrade_method: Optional[str] = REQ(
         default=None, str_validator=check_string_in(VALID_DOWNGRADE_METHODS)
     ),
-    scrub_realm: Optional[bool] = REQ(default=None, json_validator=check_bool),
+    scrub_realm: bool = REQ(default=False, json_validator=check_bool),
     query: Optional[str] = REQ("q", default=None),
     org_type: Optional[int] = REQ(default=None, converter=to_non_negative_int),
 ) -> HttpResponse:
diff --git a/corporate/tests/test_stripe.py b/corporate/tests/test_stripe.py
index faa7ca7cda..22f4514aa7 100644
--- a/corporate/tests/test_stripe.py
+++ b/corporate/tests/test_stripe.py
@@ -336,12 +336,10 @@ MOCKED_STRIPE_FUNCTION_NAMES = [
 
 
 def mock_stripe(
-    tested_timestamp_fields: Sequence[str] = [], generate: Optional[bool] = None
+    tested_timestamp_fields: Sequence[str] = [], generate: bool = settings.GENERATE_STRIPE_FIXTURES
 ) -> Callable[[Callable[ParamT, ReturnT]], Callable[ParamT, ReturnT]]:
     def _mock_stripe(decorated_function: Callable[ParamT, ReturnT]) -> Callable[ParamT, ReturnT]:
         generate_fixture = generate
-        if generate_fixture is None:
-            generate_fixture = settings.GENERATE_STRIPE_FIXTURES
         if generate_fixture:  # nocoverage
             assert stripe.api_key
         for mocked_function_name in MOCKED_STRIPE_FUNCTION_NAMES:
diff --git a/zerver/actions/create_realm.py b/zerver/actions/create_realm.py
index 6f19617398..fc0235a579 100644
--- a/zerver/actions/create_realm.py
+++ b/zerver/actions/create_realm.py
@@ -136,8 +136,8 @@ def do_create_realm(
     plan_type: Optional[int] = None,
     org_type: Optional[int] = None,
     date_created: Optional[datetime.datetime] = None,
-    is_demo_organization: Optional[bool] = False,
-    enable_spectator_access: Optional[bool] = False,
+    is_demo_organization: bool = False,
+    enable_spectator_access: Optional[bool] = None,
 ) -> Realm:
     if string_id == settings.SOCIAL_AUTH_SUBDOMAIN:
         raise AssertionError("Creating a realm on SOCIAL_AUTH_SUBDOMAIN is not allowed!")
diff --git a/zerver/lib/cache.py b/zerver/lib/cache.py
index 8d15eca510..c67bce6de9 100644
--- a/zerver/lib/cache.py
+++ b/zerver/lib/cache.py
@@ -703,12 +703,12 @@ def flush_stream(
 def flush_used_upload_space_cache(
     *,
     instance: "Attachment",
-    created: Optional[bool] = None,
+    created: bool = True,
     **kwargs: object,
 ) -> None:
     attachment = instance
 
-    if created is None or created:
+    if created:
         cache_delete(get_realm_used_upload_space_cache_key(attachment.owner.realm))
 
 
diff --git a/zerver/lib/markdown/help_relative_links.py b/zerver/lib/markdown/help_relative_links.py
index 3c0ba8fff3..a4ec8cf6f7 100644
--- a/zerver/lib/markdown/help_relative_links.py
+++ b/zerver/lib/markdown/help_relative_links.py
@@ -1,5 +1,5 @@
 import re
-from typing import Any, List, Match, Optional
+from typing import Any, List, Match
 
 from markdown import Markdown
 from markdown.extensions import Extension
@@ -81,7 +81,7 @@ class RelativeLinksHelpExtension(Extension):
         )
 
 
-relative_help_links: Optional[bool] = None
+relative_help_links: bool = False
 
 
 def set_relative_help_links(value: bool) -> None:
diff --git a/zerver/lib/markdown/help_settings_links.py b/zerver/lib/markdown/help_settings_links.py
index 768f969191..10194092cd 100644
--- a/zerver/lib/markdown/help_settings_links.py
+++ b/zerver/lib/markdown/help_settings_links.py
@@ -1,5 +1,5 @@
 import re
-from typing import Any, List, Match, Optional
+from typing import Any, List, Match
 
 from markdown import Markdown
 from markdown.extensions import Extension
@@ -114,7 +114,7 @@ class SettingHelpExtension(Extension):
         md.preprocessors.register(Setting(), "setting", PREPROCESSOR_PRIORITES["setting"])
 
 
-relative_settings_links: Optional[bool] = None
+relative_settings_links: bool = False
 
 
 def set_relative_settings_links(value: bool) -> None:
diff --git a/zerver/lib/types.py b/zerver/lib/types.py
index 66544dcdce..62a7930cd3 100644
--- a/zerver/lib/types.py
+++ b/zerver/lib/types.py
@@ -186,7 +186,7 @@ class SubscriptionStreamDict(TypedDict):
     email_notifications: Optional[bool]
     first_message_id: Optional[int]
     history_public_to_subscribers: bool
-    in_home_view: Optional[bool]
+    in_home_view: bool
     # Bug: invite_only should be bool.
     invite_only: Optional[bool]
     is_announcement_only: bool