diff --git a/utils/mdhtml/lib.rs b/utils/mdhtml/lib.rs
index 1439ebd6..4eef71bd 100644
--- a/utils/mdhtml/lib.rs
+++ b/utils/mdhtml/lib.rs
@@ -51,12 +51,15 @@ impl TokenSink for Sink {
 							}
 						},
 						"a" => {
-							let any_attr = !tag.attrs.is_empty();
+							let mut any_attr = !tag.attrs.is_empty();
 							for attr in tag.attrs {
 								match attr.name.local.as_ref() {
 									"href" => self.buffer.push_str(&format!(" href=\"{}\"", attr.value.as_ref())),
 									"title" => self.buffer.push_str(&format!(" title=\"{}\"", attr.value.as_ref())),
-									"class" => if attr.value.as_ref() == "u-url mention" { self.buffer.push_str(" class=\"u-url mention\"") },
+									"class" => if attr.value.as_ref() == "u-url mention" {
+										any_attr = false;
+										self.buffer.push_str(" class=\"u-url mention\"")
+									},
 									_ => {},
 								}
 							}