diff --git a/app/controllers/dmsf_files_controller.rb b/app/controllers/dmsf_files_controller.rb
index 49d9d766..49fe0451 100644
--- a/app/controllers/dmsf_files_controller.rb
+++ b/app/controllers/dmsf_files_controller.rb
@@ -81,7 +81,7 @@ class DmsfFilesController < ApplicationController
       send_file pdf_preview, filename: "#{basename}.pdf", type: 'application/pdf', disposition: 'inline'
     # Text preview
     elsif !api_request? && params[:download].blank? && (@file.size <= Setting.file_max_size_displayed.to_i.kilobyte) &&
-          (@file.text? || @file.markdown? || @file.textile?) && !@file.html?
+          (@file.text? || @file.markdown? || @file.textile?) && !@file.html? && formats.include?(:html)
       @content = File.read(@revision.disk_file, mode: 'rb')
       render action: 'document'
     # Offer the file for download
diff --git a/test/functional/dmsf_files_controller_test.rb b/test/functional/dmsf_files_controller_test.rb
index f29ef98d..8a67c2bb 100644
--- a/test/functional/dmsf_files_controller_test.rb
+++ b/test/functional/dmsf_files_controller_test.rb
@@ -61,13 +61,20 @@ class DmsfFilesControllerTest < RedmineDmsf::Test::TestCase
     assert_response :forbidden
   end
 
-  def test_view_file_ok
+  def test_view_file_standard_url
     # Permissions OK
     post '/login', params: { username: 'jsmith', password: 'jsmith' }
     get "/dmsf/files/#{@file1.id}/view", params: { id: @file1.id }
     assert_response :success
   end
 
+  def test_view_file_pretty_url
+    # Permissions OK
+    post '/login', params: { username: 'jsmith', password: 'jsmith' }
+    get "/dmsf/files/#{@file1.id}/test.txt", params: { id: @file1.id }
+    assert_response :success
+  end
+
   def test_view_file_forbidden
     # Missing permissions
     post '/login', params: { username: 'jsmith', password: 'jsmith' }