diff --git a/cgi-bin/form.py b/cgi-bin/form.py
index 5ca8b69..9fd4268 100755
--- a/cgi-bin/form.py
+++ b/cgi-bin/form.py
@@ -131,15 +131,16 @@ if form_disabled:
 form = cgi.FieldStorage()
 
 @overload
-def get_form_value(name: str, default: Optional[str], cast: type[str] = str) -> str: ...
+def get_form_value(name: str, default: None = ..., *, cast: type[bytes]) -> tuple[str, bytes]:...
 @overload
-def get_form_value(name: str, default: Optional[int], cast: type[int]) -> int:...
+def get_form_value(name: str, default: Optional[int] = ..., *, cast: type[int]) -> int:...
 @overload
-def get_form_value(name: str, default: None = ..., cast: type[bytes] = ...) -> tuple[str, bytes]:...
+def get_form_value(name: str, default: Optional[str] = ..., *, cast: type[str] = ...) -> str: ...
 def get_form_value(
 	name: str,
 	default: Any = None,
-	cast: type[str] | type[int] | type[io.BytesIO] = str,
+	*,
+	cast: type[str] | type[int] | type[bytes] = str,
 ) -> Any:
 	if name not in form:
 		if default is None:
@@ -166,7 +167,7 @@ def get_form_value(
 # constant-time string comparison here.
 given_csrf_token = get_form_value("csrftoken")
 if not hmac.compare_digest(csrf_token, given_csrf_token):
-	fail("400 Bad Request", f"Invalid CSRF token")
+	fail("400 Bad Request", "Invalid CSRF token")
 
 
 # If the honeypot field was not empty, back off.
@@ -194,7 +195,7 @@ if not EMAIL_REGEX.fullmatch(contact_email):
 message = get_form_value("message", "[Keine Nachricht hinterlassen]")
 attachment: Optional[tuple[str, bytes]] = None
 
-ticket_details = collections.OrderedDict()
+ticket_details = collections.OrderedDict[str, str | int]()
 ticket_details["Kontaktperson"] = contact_name
 ticket_details["Email"] = contact_email
 
@@ -220,9 +221,9 @@ match request_uri:
 		ticket_details["Adresse"] = get_form_value("addressline")
 		ticket_details["PLZ"] = get_form_value("postalcode")
 		ticket_details["Stadt"] = get_form_value("city")
-		ticket_details["Anzahl Desktops"] = get_form_value("desktopcount", 0, int)
-		ticket_details["Anzahl Laptops"] = get_form_value("laptopcount", 0, int)
-		ticket_details["Anzahl Drucker"] = get_form_value("printercount", 0, int)
+		ticket_details["Anzahl Desktops"] = get_form_value("desktopcount", 0, cast=int)
+		ticket_details["Anzahl Laptops"] = get_form_value("laptopcount", 0, cast=int)
+		ticket_details["Anzahl Drucker"] = get_form_value("printercount", 0, cast=int)
 
 	case "/computer-beantragen/privat":
 		form_name = "Computerantrag (privat)"
@@ -256,13 +257,13 @@ match request_uri:
 		ticket_details["Teilnehmenden-Name"] = get_form_value("participantname", "-")
 		ticket_details["Telefonnummer"] = get_form_value("contactphone", "-")
 		ticket_details["Fotos?"] = get_form_value("photos")
-	
+
 	case "/party":
 		form_name = "CoderDojo Minecraft LAN"
 		form_group = "CoderDojo"
 		ticket_details["Java-Spielername"] = get_form_value("javaname", "")
 		ticket_details["Bedrock-Spielername"] = get_form_value("bedrockname", "")
-	
+
 	case "/freizeit":
 		form_name = "CoderCamp Umfrage"
 		form_group = "CoderDojo"