diff --git a/biscuit/apps/chronos/migrations/0005_school_related.py b/biscuit/apps/chronos/migrations/0005_school_related.py
index d30597a55d45f3f8998675d4a0853c7309efaeac..90e8920fe24bf05f133a5808a537451afd3798a5 100644
--- a/biscuit/apps/chronos/migrations/0005_school_related.py
+++ b/biscuit/apps/chronos/migrations/0005_school_related.py
@@ -16,32 +16,32 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='lesson',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AddField(
             model_name='lessonperiod',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AddField(
             model_name='lessonsubstitution',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AddField(
             model_name='room',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AddField(
             model_name='subject',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AddField(
             model_name='timeperiod',
             name='school',
-            field=models.ForeignKey(default=biscuit.core.util.core_helpers.get_current_school, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='core.School'),
         ),
         migrations.AlterField(
             model_name='room',
diff --git a/biscuit/apps/chronos/templates/chronos/tt_week.html b/biscuit/apps/chronos/templates/chronos/tt_week.html
index 3a2f80f4de5268c24cce0e2786ac39225386876e..d21cefb741e92349117fc868538a85acee7bdccd 100644
--- a/biscuit/apps/chronos/templates/chronos/tt_week.html
+++ b/biscuit/apps/chronos/templates/chronos/tt_week.html
@@ -1,6 +1,6 @@
 {# -*- engine:django -*- #}
 {% extends "core/base.html" %}
-{% load bootstrap4 data_helpers i18n staticfiles %}
+{% load bootstrap4 data_helpers font_awesome i18n staticfiles %}
 
 {% block bootstrap4_extra_head %}
  {{ block.super }}
diff --git a/biscuit/apps/chronos/views.py b/biscuit/apps/chronos/views.py
index 6fa61d1227b1203e3337aa3c9ad48000ace91ff4..73a517d1f3c37b80ad9df87ac9d2ab6625ce89c7 100644
--- a/biscuit/apps/chronos/views.py
+++ b/biscuit/apps/chronos/views.py
@@ -31,7 +31,13 @@ def timetable(request: HttpRequest, week: Optional[int] = None) -> HttpResponse:
     lesson_periods = LessonPeriod.objects.filter(
         lesson__date_start__gte=week_days(wanted_week)[0],
         lesson__date_end__lte=week_days(wanted_week)[-1]
-    ).extra(select={'_week': wanted_week})
+    ).select_related(
+        'period', 'lesson'
+    ).prefetch_related(
+        'substitutions'
+    ).extra(
+        select={'_week': wanted_week}
+    )
 
     if request.GET.get('group', None) or request.GET.get('teacher', None) or request.GET.get('room', None):
         # Incrementally filter lesson periods by GET parameters