diff --git a/backend/src/api/webmention.rs b/backend/src/api/webmention.rs
index feaf5d1..71c69aa 100644
--- a/backend/src/api/webmention.rs
+++ b/backend/src/api/webmention.rs
@@ -117,7 +117,7 @@ pub fn lookup_target(conn: MainDatabase, target: String) -> Result<Json<Vec<WebM
             .map_err(Error::Database)?
             .into_iter()
             .map(Into::into)
-            .filter(|wm| {
+            .filter(|wm: &WebMention| {
                 !wm.source.contains("like/twitter") || !wm.source.contains("like/mastodon")
             })
             .collect::<Vec<WebMention>>(),