diff --git a/aleksis/apps/kort/models.py b/aleksis/apps/kort/models.py
index 64b2d36941336a588e2af31a83ad23f38f6bb2ac..11e2e03d521202339c1c5f155b6a05d3b97ee60d 100644
--- a/aleksis/apps/kort/models.py
+++ b/aleksis/apps/kort/models.py
@@ -102,7 +102,6 @@ class Card(ExtensibleModel):
     pdf_file = models.FileField(
         verbose_name=_("PDF file"),
         blank=True,
-        null=True,
         upload_to="cards/",
         validators=[FileExtensionValidator(["pdf"])],
     )
diff --git a/aleksis/apps/kort/templatetags/barcode.py b/aleksis/apps/kort/templatetags/barcode.py
index 9468d1dc8a32aea23371afc27f39fe9a844a7364..0696c4d0a74cf3d3c8ceb6cbe519bd9e05b74561 100644
--- a/aleksis/apps/kort/templatetags/barcode.py
+++ b/aleksis/apps/kort/templatetags/barcode.py
@@ -7,6 +7,7 @@ import barcode
 
 register = template.Library()
 
+
 # Adapted by https://stackoverflow.com/questions/62244670/print-barcode-in-pdf-with-django
 @register.simple_tag
 def generate_barcode(uid):
@@ -25,4 +26,4 @@ def generate_barcode(uid):
     rv.readline()
     # read the svg tag into a string
     svg = rv.read()
-    return mark_safe(svg.decode("utf-8"))
+    return mark_safe(svg.decode("utf-8"))  # noqa
diff --git a/aleksis/apps/kort/views.py b/aleksis/apps/kort/views.py
index 0c088a9fa89b4f0a19c905782c623f44c8234319..1741e6e3bac558d9373d0b35eed4c600b409011c 100644
--- a/aleksis/apps/kort/views.py
+++ b/aleksis/apps/kort/views.py
@@ -95,7 +95,7 @@ class CardGeneratePDFView(PermissionRequiredMixin, RevisionMixin, SingleObjectMi
         redirect_url = reverse("card", args=[self.object.pk])
         result = self.object.generate_pdf()
 
-        if result == True:
+        if result is True:
             return redirect(redirect_url)
 
         return render_progress_page(
diff --git a/pyproject.toml b/pyproject.toml
index 26f3f32a271f19e1cdc79301ca8d2688ad44e314..3a8aeadebfccd01dbdab1fc6226284d985120f27 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,11 +25,11 @@ secondary = true
 
 [tool.poetry.dependencies]
 python = "^3.9"
-aleksis-core = "^2.0"
+aleksis-core = "^2.8"
 python-barcode = "^0.13.1"
 
 [tool.poetry.dev-dependencies]
-aleksis-builddeps = "^5"
+aleksis-builddeps = "*"
 
 [tool.poetry.plugins."aleksis.app"]
 kort = "aleksis.apps.kort.apps:DefaultConfig"