diff --git a/app/controllers/exercises_controller.rb b/app/controllers/exercises_controller.rb
index 9de91ca0e..cc7756ca2 100644
--- a/app/controllers/exercises_controller.rb
+++ b/app/controllers/exercises_controller.rb
@@ -1294,7 +1294,7 @@ class ExercisesController < ApplicationController
             get_export_users(@exercise,@course,@export_ex_users)
             exercise_export_name = "#{current_user.real_name}_#{@course.name}_#{@exercise.exercise_name}"
             ex_xlsx = render_to_string handlers: [:axlsx], formats: [:xlsx], template: "exercises/exercise_lists.xlsx.axlsx", locals: {table_columns:@table_columns,exercise_users:@user_columns}
-            zip_file = Tempfile.new(["#{exercise_export_name}","xlsx"],"/home/tmp")
+            zip_file = Tempfile.new(exercise_export_name,"/home/tmp")
             zip_file.write(ex_xlsx)
             zip_file.close
             # render json{:status => 0,"file_name":"#{exercise_export_name}"}