diff --git a/serde_codegen/src/de.rs b/serde_codegen/src/de.rs
index 19a32483..3f949df0 100644
--- a/serde_codegen/src/de.rs
+++ b/serde_codegen/src/de.rs
@@ -676,6 +676,7 @@ fn deserialize_struct_variant(
                 $visit_seq_expr
             }
 
+            #[inline]
             fn visit_map<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
                 where __V: ::serde::de::MapVisitor,
             {