diff --git a/tests/color.rs b/tests/color.rs
index 2c9a93b..f01c922 100644
--- a/tests/color.rs
+++ b/tests/color.rs
@@ -471,3 +471,8 @@ test!(
     "a {\n  color: ie-hex-str(rgba(0, 255, 0, 0.5));\n}\n",
     "a {\n  color: #8000FF00;\n}\n"
 );
+// test!(
+//     builtin_functions_interchangable_underscore_hyphen,
+//     "a {\n  color: ie_hex-str(rgba(0, 255, 0, 0.5));\n}\n",
+//     "a {\n  color: #8000FF00;\n}\n"
+// );