diff --git a/app/item/views.py b/app/item/views.py
index 8452429..a65ccf7 100644
--- a/app/item/views.py
+++ b/app/item/views.py
@@ -2,7 +2,6 @@ import json
 import xml.etree.ElementTree as ET
 
 import ox
-import isoweek
 
 from django.utils import timezone
 from django.utils.timezone import datetime, timedelta
@@ -50,7 +49,7 @@ def get_byline(week):
 
 def get_weeks(archive):
     weeks = sorted(set(archive.values_list('year', 'week')))
-    weeks = [isoweek.Week(*w).monday().strftime('%Y-%m-%d') for w in weeks]
+    weeks = [datetime.strptime('%s-W%s-1' % w, "%Y-W%U-%w").strftime('%Y-%m-%d') for w in weeks]
     weeks = [{
         'date': week,
         'year': week.split('-')[0],
@@ -90,7 +89,7 @@ def archive(request, year=None, month=None, day=None, week=None):
     archive = models.Item.all_public()
     if year and month and day:
         date = datetime.strptime('%s-%s-%s' % (year, month, day), '%Y-%m-%d')
-        week = date.isocalendar()[1]
+        week = int(date.strftime('%U'))
         year = int(year)
         archive_week = archive.filter(year=year, week=week).order_by('published')
         years = {}
diff --git a/app/listmonk/utils.py b/app/listmonk/utils.py
index 657c04d..001fa5a 100644
--- a/app/listmonk/utils.py
+++ b/app/listmonk/utils.py
@@ -23,8 +23,7 @@ def get_auth(headers):
 
 def send_week(monday):
     from . import views
-    date = datetime.strptime(date, '%Y-%m-%d')
-    monday = views.get_monday(date)
+    monday = views.get_monday(monday)
     year, month, day = monday.split('-')
     body = views.week(year, month, day)
     name = 'weekly-digest-%s' % monday
diff --git a/app/listmonk/views.py b/app/listmonk/views.py
index de71841..2aa4c80 100644
--- a/app/listmonk/views.py
+++ b/app/listmonk/views.py
@@ -34,7 +34,7 @@ def week(year, month, day):
         week=ExtractWeek('published')
     )
     date = datetime.strptime('%s-%s-%s' % (year, month, day), '%Y-%m-%d')
-    week = date.isocalendar()[1]
+    week = int(date.strftime('%U'))
     year = int(year)
     archive_week = archive.filter(year=year, week=week).order_by('published')
     context['weeks'] = get_weeks(archive)
diff --git a/requirements.txt b/requirements.txt
index ce76fb5..e80dfb9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,4 +15,3 @@ redis
 django-brake
 python-telegram-bot
 ox
-isoweek