diff --git a/app/models/forum.rb b/app/models/forum.rb
index 08f1e79..af687bc 100644
--- a/app/models/forum.rb
+++ b/app/models/forum.rb
@@ -17,7 +17,7 @@ class Forum < ActiveRecord::Base
   end
 
   def can_read?(user)
-    group.can_read?(user) && (role_read.nil? || (!user.nil? && user.role >= role_read))
+    group && group.can_read?(user) && (role_read.nil? || (!user.nil? && user.role >= role_read))
   end
 
   def can_write?(user)
diff --git a/app/models/forumthread.rb b/app/models/forumthread.rb
index eb328a5..7937a02 100644
--- a/app/models/forumthread.rb
+++ b/app/models/forumthread.rb
@@ -31,7 +31,7 @@ class Forumthread < ActiveRecord::Base
   end
 
   def can_read?(user)
-    forum.can_read?(user)
+    forum && forum.can_read?(user)
   end
 
   def can_write?(user)