diff --git a/serde_derive/src/de.rs b/serde_derive/src/de.rs
index 216e4b34..87a6d5ca 100644
--- a/serde_derive/src/de.rs
+++ b/serde_derive/src/de.rs
@@ -73,6 +73,8 @@ pub fn expand_derive_deserialize(input: &syn::DeriveInput) -> Result<TokenStream
     let generated = quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
+            #[allow(unknown_lints)]
+            #[allow(rust_2018_idioms)]
             extern crate serde as _serde;
             #try_replacement
             #impl_block
diff --git a/serde_derive/src/ser.rs b/serde_derive/src/ser.rs
index c78237bf..146546de 100644
--- a/serde_derive/src/ser.rs
+++ b/serde_derive/src/ser.rs
@@ -61,6 +61,8 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
     let generated = quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
+            #[allow(unknown_lints)]
+            #[allow(rust_2018_idioms)]
             extern crate serde as _serde;
             #try_replacement
             #impl_block