diff --git a/test/unit/lib/redmine/helpers/url_test.rb b/test/unit/lib/redmine/helpers/url_test.rb
index f8f1a0732..af415402f 100644
--- a/test/unit/lib/redmine/helpers/url_test.rb
+++ b/test/unit/lib/redmine/helpers/url_test.rb
@@ -27,6 +27,7 @@ class URLTest < ActiveSupport::TestCase
     assert uri_with_safe_scheme?("https://example.com/")
     assert uri_with_safe_scheme?("ftp://example.com/index.html")
     assert uri_with_safe_scheme?("mailto:root@example.com")
+    assert uri_with_safe_scheme?("tel:+1234567890")
   end
 
   def test_uri_with_safe_scheme_invalid_component