diff --git a/serde_derive/src/de.rs b/serde_derive/src/de.rs
index 85c2194b3..5c52b24ba 100644
--- a/serde_derive/src/de.rs
+++ b/serde_derive/src/de.rs
@@ -2400,7 +2400,9 @@ fn deserialize_struct_as_struct_visitor(
         .collect();
 
     let fields_stmt = {
-        let field_names = field_names_idents.iter().flat_map(|(_, _, aliases)| aliases);
+        let field_names = field_names_idents
+            .iter()
+            .flat_map(|(_, _, aliases)| aliases);
 
         quote_block! {
             const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];