diff --git a/judge/utils/problems.py b/judge/utils/problems.py
index fd1e75b..f87f807 100644
--- a/judge/utils/problems.py
+++ b/judge/utils/problems.py
@@ -39,7 +39,7 @@ def user_completed_ids(profile):
     if result is None:
         result = set(Submission.objects.filter(user=profile, result='AC', points=F('problem__points'))
                      .values_list('problem_id', flat=True).distinct())
-        cache.set(key, result, 300)
+        cache.set(key, result, 86400)
     return result
 
 
@@ -65,7 +65,7 @@ def user_attempted_ids(profile):
                                                  .values_list('problem__id', 'problem__points')
                                                  .annotate(points=Max('points'))
                                                  .filter(points__lt=F('problem__points')))}
-        cache.set(key, result, 300)
+        cache.set(key, result, 86400)
     return result
 
 
diff --git a/requirements.txt b/requirements.txt
index 564fa30..a7b9d9c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -33,4 +33,4 @@ sqlparse
 channels
 channels-redis
 docker
-
+python-memcached