diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..d3b5aa0
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+# https://github.com/github/linguist/blob/HEAD/docs/overrides.md
+test/**/*.html linguist-vendored