diff --git a/spec/example/example_order.ttl b/spec/example/example_order.ttl
new file mode 100644
index 0000000..64fa977
--- /dev/null
+++ b/spec/example/example_order.ttl
@@ -0,0 +1,24 @@
+<https://example.org/a> a <https://example.org/b>.
+<https://example.org/a> <http://purl.org/dc/terms/title> "test title".
+<https://example.org/a/b/> a <https://example.org/b>.
+<https://example.org/a/b/> <http://example.org/title> "test title 2/".
+<https://example.org/a/b> a <https://example.org/b>.
+<https://example.org/a/b> <http://example.org/title> "test title 2".
+<https://example.org/a/c> a <https://example.org/b>.
+<https://example.org/a/c> <http://example.org/title> "test title 3".
+<https://example.org/a/d> a <https://example.org/b>.
+<https://example.org/a/d> <http://example.org/title> "test title 4".
+<https://example.org/a/e> a <https://example.org/b>.
+<https://example.org/a/e> <http://example.org/title> "test title 5".
+<https://example.org/b> a <https://example.org/a>.
+<https://example.org/b> <http://example.org/title> "test title 6".
+<https://example.org/b> a <https://example.org/a>.
+<https://example.org/b> <http://example.org/title> "test title 6".
+<https://example.org/b/a> a <https://example.org/a>.
+<https://example.org/b/a> <http://example.org/title> "test title 6".
+<https://example.org/b/b> a <https://example.org/a>.
+<https://example.org/b/b> <http://example.org/title> "test title 6".
+<https://example.org/b/c> a <https://example.org/a>.
+<https://example.org/b/c> <http://example.org/title> "test title 6".
+<https://example.org/b/d> a <https://example.org/a>.
+<https://example.org/b/d> <http://example.org/title> "test title 6".
\ No newline at end of file
diff --git a/spec/ttl2html_spec.rb b/spec/ttl2html_spec.rb
index 80c68c6..4bce20c 100644
--- a/spec/ttl2html_spec.rb
+++ b/spec/ttl2html_spec.rb
@@ -782,6 +782,15 @@
       html = Capybara.string cont
       expect(html).to have_css("div.jumbotron div.description")
     end
+    it "should output files/dirs accurately, even in parallel execution" do
+      @ttl2html = TTL2HTML::App.new(File.join(spec_base_dir, "example", "example_content.yml"))
+      @ttl2html.load_turtle(File.join(spec_base_dir, "example", "example_order.ttl"))
+      expect {
+        @ttl2html.output_html_files
+      }.not_to raise_error
+      expect(Pathname("/tmp/html/a")).to be_directory
+      expect(Pathname("/tmp/html/b")).to be_directory
+    end
   end
   context "#output_turtle_files" do
     ttl2html = nil