diff --git a/examples/src/fail_tests/auto_covariant.stderr b/examples/src/fail_tests/auto_covariant.stderr
index b94cd24..28c7b22 100644
--- a/examples/src/fail_tests/auto_covariant.stderr
+++ b/examples/src/fail_tests/auto_covariant.stderr
@@ -9,13 +9,7 @@ error: Ouroboros cannot automatically determine if this type is covariant.
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0601]: `main` function not found in crate `$CRATE`
-  --> $DIR/auto_covariant.rs:1:1
+  --> $DIR/auto_covariant.rs:12:2
    |
-1  | / use ouroboros::self_referencing;
-2  | |
-3  | | struct NotGuaranteedCovariant<'a> {
-4  | |     data: &'a (),
-...  |
-11 | |     field: NotGuaranteedCovariant<'this>
-12 | | }
-   | |_^ consider adding a `main` function to `$DIR/src/fail_tests/auto_covariant.rs`
+12 | }
+   |  ^ consider adding a `main` function to `$DIR/src/fail_tests/auto_covariant.rs`
diff --git a/ouroboros_macro/src/generate/into_heads.rs b/ouroboros_macro/src/generate/into_heads.rs
index fd68ce2..5784e46 100644
--- a/ouroboros_macro/src/generate/into_heads.rs
+++ b/ouroboros_macro/src/generate/into_heads.rs
@@ -69,6 +69,7 @@ pub fn make_into_heads(info: &StructInfo, options: Options) -> (TokenStream, Tok
         #documentation
         #[allow(clippy::drop_ref)]
         #[allow(clippy::drop_copy)]
+        #[allow(clippy::drop_non_drop)]
         #visibility fn into_heads(self) -> Heads<#(#generic_args),*> {
             #(#code)*
             Heads {