diff --git a/Makefile b/Makefile
index e5ed6742..623f2cbd 100644
--- a/Makefile
+++ b/Makefile
@@ -67,7 +67,7 @@ test-e2e: init-db
 	$(NPM) test
 
 test-python:
-	$(PYTEST) fittrackee_api --cov-config .coveragerc --cov=fittrackee_api --cov-report term-missing
+	$(PYTEST) fittrackee_api --cov-config .coveragerc --cov=fittrackee_api --cov-report term-missing $(PYTEST_ARGS)
 
 test-python-xml:
 	$(PYTEST) fittrackee_api --cov-config .coveragerc --cov=fittrackee_api --cov-report xml
diff --git a/fittrackee_api/fittrackee_api/activities/stats.py b/fittrackee_api/fittrackee_api/activities/stats.py
index 8df8e9f3..6f840a70 100644
--- a/fittrackee_api/fittrackee_api/activities/stats.py
+++ b/fittrackee_api/fittrackee_api/activities/stats.py
@@ -76,7 +76,9 @@ def get_activities(user_id, filter_type):
             else:
                 if time == 'week':
                     activity_date = activity.activity_date - timedelta(
-                        days=activity.activity_date.isoweekday()
+                        days=(activity.activity_date.isoweekday()
+                              if activity.activity_date.isoweekday() < 7
+                              else 0)
                     )
                     time_period = datetime.strftime(activity_date, "%Y-%m-%d")
                 elif time == 'weekm':  # week start Monday
diff --git a/fittrackee_api/fittrackee_api/tests/test_stats_api.py b/fittrackee_api/fittrackee_api/tests/test_stats_api.py
index 025cac08..2f7f877b 100644
--- a/fittrackee_api/fittrackee_api/tests/test_stats_api.py
+++ b/fittrackee_api/fittrackee_api/tests/test_stats_api.py
@@ -684,7 +684,7 @@ def test_get_stats_by_week_all_activities(
                             'total_duration': 1600
                         }
                 },
-            '2018-03-25':
+            '2018-04-01':
                 {
                     '1':
                         {
@@ -738,7 +738,7 @@ def test_get_stats_by_week_all_activities_week_13(
     assert 'success' in data['status']
     assert data['data']['statistics'] == \
         {
-            '2018-03-25':
+            '2018-04-01':
                 {
                     '1':
                         {