diff --git a/app/models/issue.rb b/app/models/issue.rb
index d7ef5eded..f08e73d24 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -1052,7 +1052,7 @@ class Issue < ActiveRecord::Base
 
   # Returns the number of hours spent on this issue
   def spent_hours
-    @spent_hours ||= time_entries.sum(:hours) || 0
+    @spent_hours ||= time_entries.sum(:hours) || 0.0
   end
 
   # Returns the total number of hours spent on this issue and its descendants
@@ -1107,7 +1107,7 @@ class Issue < ActiveRecord::Base
     if issues.any?
       hours_by_issue_id = TimeEntry.visible(user).where(:issue_id => issues.map(&:id)).group(:issue_id).sum(:hours)
       issues.each do |issue|
-        issue.instance_variable_set "@spent_hours", (hours_by_issue_id[issue.id] || 0)
+        issue.instance_variable_set "@spent_hours", (hours_by_issue_id[issue.id] || 0.0)
       end
     end
   end
@@ -1120,7 +1120,7 @@ class Issue < ActiveRecord::Base
           " AND parent.lft <= #{Issue.table_name}.lft AND parent.rgt >= #{Issue.table_name}.rgt").
         where("parent.id IN (?)", issues.map(&:id)).group("parent.id").sum(:hours)
       issues.each do |issue|
-        issue.instance_variable_set "@total_spent_hours", (hours_by_issue_id[issue.id] || 0)
+        issue.instance_variable_set "@total_spent_hours", (hours_by_issue_id[issue.id] || 0.0)
       end
     end
   end