diff --git a/wger/manager/models/slot_entry.py b/wger/manager/models/slot_entry.py
index dfc4a606f..711008f3e 100644
--- a/wger/manager/models/slot_entry.py
+++ b/wger/manager/models/slot_entry.py
@@ -213,6 +213,12 @@ class SlotEntry(models.Model):
                 )
             if not self.weight_rounding:
                 self.weight_rounding = self.slot.day.routine.user.userprofile.weight_rounding
+
+            # Auto-calculate order if not provided
+            if self.order is None:
+                max_order = self.slot.entries.aggregate(models.Max('order'))['order__max']
+                self.order = (max_order or 0) + 1
+
         return super().save(*args, **kwargs)
 
     def get_owner_object(self):
diff --git a/wger/manager/tests/test_slot_entry.py b/wger/manager/tests/test_slot_entry.py
index 3e148ced6..a6976986c 100644
--- a/wger/manager/tests/test_slot_entry.py
+++ b/wger/manager/tests/test_slot_entry.py
@@ -58,6 +58,24 @@ class SlotEntryTestCase(WgerTestCase):
         )
         self.slot_entry.save()
 
+    def test_auto_add_order(self):
+        """
+        Test that the order is automatically added if not provided
+        """
+        slot_entry_2 = SlotEntry(slot_id=1, exercise_id=2, order=None)
+        slot_entry_2.save()
+
+        slot_entry_3 = SlotEntry(slot_id=1, exercise_id=3, order=7)
+        slot_entry_3.save()
+
+        slot_entry_4 = SlotEntry(slot_id=1, exercise_id=3)
+        slot_entry_4.save()
+
+        self.assertEqual(self.slot_entry.order, 1)
+        self.assertEqual(slot_entry_2.order, 2)
+        self.assertEqual(slot_entry_3.order, 7)
+        self.assertEqual(slot_entry_4.order, 8)
+
     def test_weight_config(self):
         """
         Test that the weight is correctly calculated for each step / iteration