diff --git a/app/models/card/entropy.rb b/app/models/card/entropy.rb
index 5f21dd63f..51b1e54a4 100644
--- a/app/models/card/entropy.rb
+++ b/app/models/card/entropy.rb
@@ -23,6 +23,6 @@ class Card::Entropy
   end
 
   def days_before_reminder
-    (auto_clean_period * 0.25).round
+    (auto_clean_period * 0.25).seconds.in_days.round
   end
 end