diff --git a/app/models/image.rb b/app/models/image.rb
index 577e6c2..66857a5 100644
--- a/app/models/image.rb
+++ b/app/models/image.rb
@@ -14,7 +14,7 @@ class Image < ApplicationRecord
                     }
   # before_post_process :rename_file
   validates_attachment_content_type :image, content_type: /\Aimage/
-  validates_attachment_file_name :image, matches: [/png\z/, /jpe?g\z/]
+  validates_attachment_file_name :image, matches: [/png\z/, /jpe?g\z/, /PNG\z/, /JPE?G\z/]
   do_not_validate_attachment_file_type :image
   scope :by_image_type, ->(type) { where(imageable_type: type) }
   scope :by_position_desc, -> { order(position: :desc) }