diff --git a/helpdesk/models.py b/helpdesk/models.py
index b585f9ea..00a92aa3 100644
--- a/helpdesk/models.py
+++ b/helpdesk/models.py
@@ -1000,8 +1000,11 @@ class FollowUp(models.Model):
         return u"%s#followup%s" % (self.ticket.get_absolute_url(), self.id)
 
     def save(self, *args, **kwargs):
+        now = timezone.now()
         t = self.ticket
-        t.modified = timezone.now()
+        if helpdesk_settings.FOLLOWUP_TIME_SPENT_AUTO and not self.time_spent:
+            self.time_spent = now - t.modified
+        t.modified = now
         t.save()
         super(FollowUp, self).save(*args, **kwargs)
 
diff --git a/helpdesk/settings.py b/helpdesk/settings.py
index cf5ca644..511109d7 100644
--- a/helpdesk/settings.py
+++ b/helpdesk/settings.py
@@ -151,6 +151,11 @@ TICKET_PRIORITY_CHOICES = getattr(settings,
                                   'HELPDESK_TICKET_PRIORITY_CHOICES',
                                   DEFAULT_TICKET_PRIORITY_CHOICES)
 
+# Follow-ups automatic time_spent calculation
+FOLLOWUP_TIME_SPENT_AUTO = getattr(settings,
+                                   'HELPDESK_FOLLOWUP_TIME_SPENT_AUTO',
+                                   False)
+
 ############################
 # options for public pages #
 ############################