diff --git a/app/models/dmsf_file.rb b/app/models/dmsf_file.rb
index 44be7f9f..a38533f4 100644
--- a/app/models/dmsf_file.rb
+++ b/app/models/dmsf_file.rb
@@ -465,7 +465,7 @@ class DmsfFile < ActiveRecord::Base
   end
 
   def disposition
-    (image? || pdf?) ? 'inline' : 'attachment'
+    (image? || pdf? || video?) ? 'inline' : 'attachment'
   end
 
   def preview(limit)
diff --git a/test/unit/dmsf_file_test.rb b/test/unit/dmsf_file_test.rb
index fd7c1548..74ba252b 100644
--- a/test/unit/dmsf_file_test.rb
+++ b/test/unit/dmsf_file_test.rb
@@ -186,9 +186,15 @@ class DmsfFileTest < RedmineDmsf::Test::UnitTest
   end
 
   def test_disposition
+    # Text
     assert_equal 'attachment', @file1.disposition
+    # Image
     assert_equal 'inline', @file7.disposition
+    # PDF
     assert_equal 'inline', @file8.disposition
+    # Video
+    @file1.last_revision.disk_filename = 'test.mp4'
+    assert_equal 'inline', @file1.disposition
   end
 
   def test_image