diff --git a/biscuit/apps/chronos/models.py b/biscuit/apps/chronos/models.py
index 8ebf484e7fc1fc9a24538d50ebed5d52da11423b..436c27d82ea10bb92fc9821b3098dffffe1e53d6 100644
--- a/biscuit/apps/chronos/models.py
+++ b/biscuit/apps/chronos/models.py
@@ -85,6 +85,27 @@ class LessonPeriod(models.Model):
     substitution = models.OneToOneField('LessonSubstitution', models.CASCADE,
                                         'lesson_period', null=True)
 
+    def get_subject(self):
+        if self.substitution:
+            return self.substitution.subject
+        else:
+            return self.lesson.subject
+
+    def get_teachers(self):
+        if self.substitution:
+            return self.substitution.teachers
+        else:
+            return self.lesson.teachers
+
+    def get_room(self):
+        if self.substitution:
+            return self.substitution.room
+        else:
+            return self.room
+
+    def get_groups(self):
+        return self.lesson.groups
+
 
 class LessonSubstitution(models.Model):
     subject = models.ForeignKey(
diff --git a/biscuit/apps/chronos/templates/chronos/tt_lesson.html b/biscuit/apps/chronos/templates/chronos/tt_lesson.html
index 9993ee75a52c50eeff78930799aae368b9a00c34..347031d0b32b71c2f4917818383830b61a001568 100644
--- a/biscuit/apps/chronos/templates/chronos/tt_lesson.html
+++ b/biscuit/apps/chronos/templates/chronos/tt_lesson.html
@@ -1,4 +1,8 @@
-<div class="card chronos-lesson"
+<div class="card chronos-lesson
+  {% if lesson_period.substitution %}
+   border border-warning
+  {% endif %}
+ "
  style="
   {% if lesson_period.lesson.subject.colour_fg %}
    color: {{ lesson_period.lesson.subject.colour_fg }};
@@ -10,17 +14,19 @@
  <div class="card-body">
   <div class="row">
    <div class="col-sm">
-    <span class="card-title">{{ lesson_period.lesson.subject.abbrev }}</span>
+    <span class="card-title">
+     {{ lesson_period.get_subject.abbrev }}
+    </span>
    </div>
   </div>
   <div class="row">
    <div class="col-sm">
-    {% for group in lesson_period.lesson.groups.all %}
+    {% for group in lesson_period.get_groups.all %}
      <span class="card-text">{{ group.short_name }}</span>
     {% endfor %}
    </div>
    <div class="col-sm">
-    {% for teacher in lesson_period.lesson.teachers.all %}
+    {% for teacher in lesson_period.get_teachers.all %}
      <a href="{% url 'person_by_id' teacher.id %}"
       title="{{ teacher.first_name }} {{ teacher.last_name }}"
       class="card-text"
@@ -30,7 +36,7 @@
     {% endfor %}
    </div>
    <div class="col-sm">
-    <span class="card-text">{{ lesson_period.room.short_name }}</span>
+    <span class="card-text">{{ lesson_period.get_room.short_name }}</span>
    </div>
   </div>
  </div>