diff --git a/calendarweek/django.py b/calendarweek/django.py
index 8a6db3c13e9aa6d89793d99627ab360f52240a47..8a582605081df5e9bafaff100f547a7ae65c3203 100644
--- a/calendarweek/django.py
+++ b/calendarweek/django.py
@@ -88,7 +88,7 @@ def i18n_js(request: HttpRequest) -> HttpResponse:
 
     # Begin day names at this element
     # 0 (default = Monday, 6 = Sunday
-    first_day = request.GET.get("first_day", 0)
+    first_day = int(request.GET.get("first_day", "0"))
     day_indices = list(range(first_day, 7)) + list(range(0, first_day))
     def reorder(l: List[Any], i: List[int]) -> List[Any]:
         return [l[n] for n in i]
diff --git a/pyproject.toml b/pyproject.toml
index c62ce06dcdaeb9801852d60ff2ae4cbbe109e057..55f4cd0da4c69639ef7ac9ead86eff1853e7fb1b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "calendarweek"
-version = "0.3.0"
+version = "0.3.1"
 description = "Utilities for working with calendar weeks in Python and Django"
 authors = ["Dominik George <nik@naturalnet.de>", "Jonathan Weth <git@jonathanweth.de>"]
 license = "MIT"