diff --git a/clippy_lints/src/iter_without_into_iter.rs b/clippy_lints/src/iter_without_into_iter.rs
index 88042525c4f75..4b39f1d9f47fe 100644
--- a/clippy_lints/src/iter_without_into_iter.rs
+++ b/clippy_lints/src/iter_without_into_iter.rs
@@ -19,6 +19,11 @@ declare_clippy_lint! {
     /// It's not bad, but having them is idiomatic and allows the type to be used in for loops directly
     /// (`for val in &iter {}`), without having to first call `iter()` or `iter_mut()`.
     ///
+    /// ### Limitations
+    /// This lint focuses on providing an idiomatic API. Therefore, it will only
+    /// lint on types which are accessible outside of the crate. For internal types,
+    /// the `IntoIterator` trait can be implemented on demand if it is actually needed.
+    ///
     /// ### Example
     /// ```no_run
     /// struct MySlice<'a>(&'a [u8]);
@@ -61,6 +66,14 @@ declare_clippy_lint! {
     /// by just calling `.iter()`, instead of the more awkward `<&Type>::into_iter` or `(&val).into_iter()` syntax
     /// in case of ambiguity with another `IntoIterator` impl.
     ///
+    /// ### Limitations
+    /// This lint focuses on providing an idiomatic API. Therefore, it will only
+    /// lint on types which are accessible outside of the crate. For internal types,
+    /// these methods can be added on demand if they are actually needed. Otherwise,
+    /// it would trigger the [`dead_code`] lint for the unused method.
+    ///
+    /// [`dead_code`]: https://doc.rust-lang.org/rustc/lints/listing/warn-by-default.html#dead-code
+    ///
     /// ### Example
     /// ```no_run
     /// struct MySlice<'a>(&'a [u8]);
@@ -104,6 +117,12 @@ fn is_nameable_in_impl_trait(ty: &rustc_hir::Ty<'_>) -> bool {
     !matches!(ty.kind, TyKind::OpaqueDef(..))
 }
 
+fn is_ty_exported(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
+    ty.ty_adt_def()
+        .and_then(|adt| adt.did().as_local())
+        .is_some_and(|did| cx.effective_visibilities.is_exported(did))
+}
+
 /// Returns the deref chain of a type, starting with the type itself.
 fn deref_chain<'cx, 'tcx>(cx: &'cx LateContext<'tcx>, ty: Ty<'tcx>) -> impl Iterator<Item = Ty<'tcx>> + 'cx {
     iter::successors(Some(ty), |&ty| {
@@ -154,6 +173,7 @@ impl LateLintPass<'_> for IterWithoutIntoIter {
                     None
                 }
             })
+            && is_ty_exported(cx, ty)
         {
             span_lint_and_then(
                 cx,
@@ -226,6 +246,7 @@ impl {self_ty_without_ref} {{
             )
             // Only lint if the `IntoIterator` impl doesn't actually exist
             && !implements_trait(cx, ref_ty, into_iter_did, &[])
+            && is_ty_exported(cx, ref_ty.peel_refs())
         {
             let self_ty_snippet = format!("{borrow_prefix}{}", snippet(cx, imp.self_ty.span, ".."));
 
@@ -247,8 +268,8 @@ impl {self_ty_without_ref} {{
 "
 impl IntoIterator for {self_ty_snippet} {{
     type IntoIter = {ret_ty};
-    type Iter = {iter_ty};
-    fn into_iter() -> Self::IntoIter {{
+    type Item = {iter_ty};
+    fn into_iter(self) -> Self::IntoIter {{
         self.iter()
     }}
 }}
diff --git a/tests/ui/into_iter_without_iter.rs b/tests/ui/into_iter_without_iter.rs
index e6ff821a8ad04..448d0114dff82 100644
--- a/tests/ui/into_iter_without_iter.rs
+++ b/tests/ui/into_iter_without_iter.rs
@@ -3,127 +3,117 @@
 
 use std::iter::IntoIterator;
 
-fn main() {
-    {
-        struct S;
-
-        impl<'a> IntoIterator for &'a S {
-            //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter` method
-            type IntoIter = std::slice::Iter<'a, u8>;
-            type Item = &'a u8;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
-        impl<'a> IntoIterator for &'a mut S {
-            //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
-            type IntoIter = std::slice::IterMut<'a, u8>;
-            type Item = &'a mut u8;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+pub struct S1;
+impl<'a> IntoIterator for &'a S1 {
+    //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter` method
+    type IntoIter = std::slice::Iter<'a, u8>;
+    type Item = &'a u8;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
     }
-    {
-        struct S<T>(T);
-        impl<'a, T> IntoIterator for &'a S<T> {
-            //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter` method
-            type IntoIter = std::slice::Iter<'a, T>;
-            type Item = &'a T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
-        impl<'a, T> IntoIterator for &'a mut S<T> {
-            //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
-            type IntoIter = std::slice::IterMut<'a, T>;
-            type Item = &'a mut T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+}
+impl<'a> IntoIterator for &'a mut S1 {
+    //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
+    type IntoIter = std::slice::IterMut<'a, u8>;
+    type Item = &'a mut u8;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
     }
-    {
-        // Both iter and iter_mut methods exist, don't lint
-        struct S<'a, T>(&'a T);
-
-        impl<'a, T> S<'a, T> {
-            fn iter(&self) -> std::slice::Iter<'a, T> {
-                todo!()
-            }
-            fn iter_mut(&mut self) -> std::slice::IterMut<'a, T> {
-                todo!()
-            }
-        }
+}
 
-        impl<'a, T> IntoIterator for &S<'a, T> {
-            type IntoIter = std::slice::Iter<'a, T>;
-            type Item = &'a T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+pub struct S2<T>(T);
+impl<'a, T> IntoIterator for &'a S2<T> {
+    //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter` method
+    type IntoIter = std::slice::Iter<'a, T>;
+    type Item = &'a T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
+impl<'a, T> IntoIterator for &'a mut S2<T> {
+    //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
+    type IntoIter = std::slice::IterMut<'a, T>;
+    type Item = &'a mut T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
 
-        impl<'a, T> IntoIterator for &mut S<'a, T> {
-            type IntoIter = std::slice::IterMut<'a, T>;
-            type Item = &'a mut T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+// Both iter and iter_mut methods exist, don't lint
+pub struct S3<'a, T>(&'a T);
+impl<'a, T> S3<'a, T> {
+    fn iter(&self) -> std::slice::Iter<'a, T> {
+        todo!()
+    }
+    fn iter_mut(&mut self) -> std::slice::IterMut<'a, T> {
+        todo!()
+    }
+}
+impl<'a, T> IntoIterator for &S3<'a, T> {
+    type IntoIter = std::slice::Iter<'a, T>;
+    type Item = &'a T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
+impl<'a, T> IntoIterator for &mut S3<'a, T> {
+    type IntoIter = std::slice::IterMut<'a, T>;
+    type Item = &'a mut T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
     }
-    {
-        // Only `iter` exists, no `iter_mut`
-        struct S<'a, T>(&'a T);
+}
 
-        impl<'a, T> S<'a, T> {
-            fn iter(&self) -> std::slice::Iter<'a, T> {
-                todo!()
-            }
-        }
+// Only `iter` exists, no `iter_mut`
+pub struct S4<'a, T>(&'a T);
 
-        impl<'a, T> IntoIterator for &S<'a, T> {
-            type IntoIter = std::slice::Iter<'a, T>;
-            type Item = &'a T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+impl<'a, T> S4<'a, T> {
+    fn iter(&self) -> std::slice::Iter<'a, T> {
+        todo!()
+    }
+}
 
-        impl<'a, T> IntoIterator for &mut S<'a, T> {
-            //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
-            type IntoIter = std::slice::IterMut<'a, T>;
-            type Item = &'a mut T;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+impl<'a, T> IntoIterator for &S4<'a, T> {
+    type IntoIter = std::slice::Iter<'a, T>;
+    type Item = &'a T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
     }
-    {
-        // `iter` exists, but `IntoIterator` is implemented for an alias. inherent_impls doesn't "normalize"
-        // aliases so that `inherent_impls(Alias)` where `type Alias = S` returns nothing, so this can lead
-        // to fun FPs. Make sure it doesn't happen here (we're using type_of, which should skip the alias).
-        struct S;
+}
 
-        impl S {
-            fn iter(&self) -> std::slice::Iter<'static, u8> {
-                todo!()
-            }
-        }
+impl<'a, T> IntoIterator for &mut S4<'a, T> {
+    //~^ ERROR: `IntoIterator` implemented for a reference type without an `iter_mut` method
+    type IntoIter = std::slice::IterMut<'a, T>;
+    type Item = &'a mut T;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
 
-        type Alias = S;
+// `iter` exists, but `IntoIterator` is implemented for an alias. inherent_impls doesn't "normalize"
+// aliases so that `inherent_impls(Alias)` where `type Alias = S` returns nothing, so this can lead
+// to fun FPs. Make sure it doesn't happen here (we're using type_of, which should skip the alias).
+pub struct S5;
 
-        impl IntoIterator for &Alias {
-            type IntoIter = std::slice::Iter<'static, u8>;
-            type Item = &'static u8;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+impl S5 {
+    fn iter(&self) -> std::slice::Iter<'static, u8> {
+        todo!()
+    }
+}
+
+pub type Alias = S5;
+
+impl IntoIterator for &Alias {
+    type IntoIter = std::slice::Iter<'static, u8>;
+    type Item = &'static u8;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
     }
 }
 
-fn issue11635() {
+fn main() {}
+
+pub mod issue11635 {
     // A little more involved than the original repro in the issue, but this tests that it correctly
     // works for more than one deref step
 
diff --git a/tests/ui/into_iter_without_iter.stderr b/tests/ui/into_iter_without_iter.stderr
index f543d1d8e86c1..70f3f82a936c6 100644
--- a/tests/ui/into_iter_without_iter.stderr
+++ b/tests/ui/into_iter_without_iter.stderr
@@ -1,21 +1,21 @@
 error: `IntoIterator` implemented for a reference type without an `iter` method
-  --> $DIR/into_iter_without_iter.rs:10:9
+  --> $DIR/into_iter_without_iter.rs:7:1
    |
-LL | /         impl<'a> IntoIterator for &'a S {
+LL | / impl<'a> IntoIterator for &'a S1 {
 LL | |
-LL | |             type IntoIter = std::slice::Iter<'a, u8>;
-LL | |             type Item = &'a u8;
+LL | |     type IntoIter = std::slice::Iter<'a, u8>;
+LL | |     type Item = &'a u8;
 ...  |
-LL | |             }
-LL | |         }
-   | |_________^
+LL | |     }
+LL | | }
+   | |_^
    |
    = note: `-D clippy::into-iter-without-iter` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::into_iter_without_iter)]`
 help: consider implementing `iter`
    |
-LL ~         
-LL + impl S {
+LL + 
+LL + impl S1 {
 LL +     fn iter(&self) -> std::slice::Iter<'a, u8> {
 LL +         <&Self as IntoIterator>::into_iter(self)
 LL +     }
@@ -23,21 +23,21 @@ LL + }
    |
 
 error: `IntoIterator` implemented for a reference type without an `iter_mut` method
-  --> $DIR/into_iter_without_iter.rs:18:9
+  --> $DIR/into_iter_without_iter.rs:15:1
    |
-LL | /         impl<'a> IntoIterator for &'a mut S {
+LL | / impl<'a> IntoIterator for &'a mut S1 {
 LL | |
-LL | |             type IntoIter = std::slice::IterMut<'a, u8>;
-LL | |             type Item = &'a mut u8;
+LL | |     type IntoIter = std::slice::IterMut<'a, u8>;
+LL | |     type Item = &'a mut u8;
 ...  |
-LL | |             }
-LL | |         }
-   | |_________^
+LL | |     }
+LL | | }
+   | |_^
    |
 help: consider implementing `iter_mut`
    |
-LL ~         
-LL + impl S {
+LL + 
+LL + impl S1 {
 LL +     fn iter_mut(&mut self) -> std::slice::IterMut<'a, u8> {
 LL +         <&mut Self as IntoIterator>::into_iter(self)
 LL +     }
@@ -45,21 +45,21 @@ LL + }
    |
 
 error: `IntoIterator` implemented for a reference type without an `iter` method
-  --> $DIR/into_iter_without_iter.rs:29:9
+  --> $DIR/into_iter_without_iter.rs:25:1
    |
-LL | /         impl<'a, T> IntoIterator for &'a S<T> {
+LL | / impl<'a, T> IntoIterator for &'a S2<T> {
 LL | |
-LL | |             type IntoIter = std::slice::Iter<'a, T>;
-LL | |             type Item = &'a T;
+LL | |     type IntoIter = std::slice::Iter<'a, T>;
+LL | |     type Item = &'a T;
 ...  |
-LL | |             }
-LL | |         }
-   | |_________^
+LL | |     }
+LL | | }
+   | |_^
    |
 help: consider implementing `iter`
    |
-LL ~         
-LL + impl S<T> {
+LL + 
+LL + impl S2<T> {
 LL +     fn iter(&self) -> std::slice::Iter<'a, T> {
 LL +         <&Self as IntoIterator>::into_iter(self)
 LL +     }
@@ -67,21 +67,21 @@ LL + }
    |
 
 error: `IntoIterator` implemented for a reference type without an `iter_mut` method
-  --> $DIR/into_iter_without_iter.rs:37:9
+  --> $DIR/into_iter_without_iter.rs:33:1
    |
-LL | /         impl<'a, T> IntoIterator for &'a mut S<T> {
+LL | / impl<'a, T> IntoIterator for &'a mut S2<T> {
 LL | |
-LL | |             type IntoIter = std::slice::IterMut<'a, T>;
-LL | |             type Item = &'a mut T;
+LL | |     type IntoIter = std::slice::IterMut<'a, T>;
+LL | |     type Item = &'a mut T;
 ...  |
-LL | |             }
-LL | |         }
-   | |_________^
+LL | |     }
+LL | | }
+   | |_^
    |
 help: consider implementing `iter_mut`
    |
-LL ~         
-LL + impl S<T> {
+LL + 
+LL + impl S2<T> {
 LL +     fn iter_mut(&mut self) -> std::slice::IterMut<'a, T> {
 LL +         <&mut Self as IntoIterator>::into_iter(self)
 LL +     }
@@ -89,21 +89,21 @@ LL + }
    |
 
 error: `IntoIterator` implemented for a reference type without an `iter_mut` method
-  --> $DIR/into_iter_without_iter.rs:93:9
+  --> $DIR/into_iter_without_iter.rs:84:1
    |
-LL | /         impl<'a, T> IntoIterator for &mut S<'a, T> {
+LL | / impl<'a, T> IntoIterator for &mut S4<'a, T> {
 LL | |
-LL | |             type IntoIter = std::slice::IterMut<'a, T>;
-LL | |             type Item = &'a mut T;
+LL | |     type IntoIter = std::slice::IterMut<'a, T>;
+LL | |     type Item = &'a mut T;
 ...  |
-LL | |             }
-LL | |         }
-   | |_________^
+LL | |     }
+LL | | }
+   | |_^
    |
 help: consider implementing `iter_mut`
    |
-LL ~         
-LL + impl S<'a, T> {
+LL + 
+LL + impl S4<'a, T> {
 LL +     fn iter_mut(&mut self) -> std::slice::IterMut<'a, T> {
 LL +         <&mut Self as IntoIterator>::into_iter(self)
 LL +     }
diff --git a/tests/ui/iter_without_into_iter.rs b/tests/ui/iter_without_into_iter.rs
index cedb756c79de1..29f526b455cb9 100644
--- a/tests/ui/iter_without_into_iter.rs
+++ b/tests/ui/iter_without_into_iter.rs
@@ -1,120 +1,124 @@
 //@no-rustfix
 #![warn(clippy::iter_without_into_iter)]
 
-fn main() {
-    {
-        struct S;
-        impl S {
-            pub fn iter(&self) -> std::slice::Iter<'_, u8> {
-                //~^ ERROR: `iter` method without an `IntoIterator` impl
-                [].iter()
-            }
-            pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
-                //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
-                [].iter_mut()
-            }
-        }
-    }
-    {
-        struct S;
-        impl S {
-            pub fn iter(&self) -> impl Iterator<Item = &u8> {
-                // RPITIT is not stable, so we can't generally suggest it here yet
-                [].iter()
-            }
-        }
-    }
-    {
-        struct S<'a>(&'a mut [u8]);
-        impl<'a> S<'a> {
-            pub fn iter(&self) -> std::slice::Iter<'_, u8> {
-                //~^ ERROR: `iter` method without an `IntoIterator` impl
-                self.0.iter()
-            }
-            pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
-                //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
-                self.0.iter_mut()
-            }
-        }
-    }
-    {
-        // Incompatible signatures
-        struct S;
-        impl S {
-            pub fn iter(self) -> std::slice::Iter<'static, u8> {
-                todo!()
-            }
-        }
-        struct S2;
-        impl S2 {
-            pub async fn iter(&self) -> std::slice::Iter<'static, u8> {
-                todo!()
-            }
-        }
-        struct S3;
-        impl S3 {
-            pub fn iter(&self, _additional_param: ()) -> std::slice::Iter<'static, u8> {
-                todo!()
-            }
-        }
-        struct S4<T>(T);
-        impl<T> S4<T> {
-            pub fn iter<U>(&self) -> std::slice::Iter<'static, (T, U)> {
-                todo!()
-            }
-        }
-        struct S5<T>(T);
-        impl<T> S5<T> {
-            pub fn iter(&self) -> std::slice::Iter<'static, T> {
-                todo!()
-            }
-        }
-    }
-    {
-        struct S<T>(T);
-        impl<T> S<T> {
-            pub fn iter(&self) -> std::slice::Iter<'_, T> {
-                //~^ ERROR: `iter` method without an `IntoIterator` impl
-                todo!()
-            }
-            pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, T> {
-                //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
-                todo!()
-            }
-        }
-    }
-    {
-        struct S<T>(T);
-        impl<T> S<T> {
-            pub fn iter(&self) -> std::slice::Iter<'_, T> {
-                // Don't lint, there's an existing (wrong) IntoIterator impl
-                todo!()
-            }
-        }
+pub struct S1;
+impl S1 {
+    pub fn iter(&self) -> std::slice::Iter<'_, u8> {
+        //~^ ERROR: `iter` method without an `IntoIterator` impl
+        [].iter()
+    }
+    pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
+        //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
+        [].iter_mut()
+    }
+}
+
+pub struct S2;
+impl S2 {
+    pub fn iter(&self) -> impl Iterator<Item = &u8> {
+        // RPITIT is not stable, so we can't generally suggest it here yet
+        [].iter()
+    }
+}
+
+pub struct S3<'a>(&'a mut [u8]);
+impl<'a> S3<'a> {
+    pub fn iter(&self) -> std::slice::Iter<'_, u8> {
+        //~^ ERROR: `iter` method without an `IntoIterator` impl
+        self.0.iter()
+    }
+    pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
+        //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
+        self.0.iter_mut()
+    }
+}
+
+// Incompatible signatures
+pub struct S4;
+impl S4 {
+    pub fn iter(self) -> std::slice::Iter<'static, u8> {
+        todo!()
+    }
+}
+
+pub struct S5;
+impl S5 {
+    pub async fn iter(&self) -> std::slice::Iter<'static, u8> {
+        todo!()
+    }
+}
+
+pub struct S6;
+impl S6 {
+    pub fn iter(&self, _additional_param: ()) -> std::slice::Iter<'static, u8> {
+        todo!()
+    }
+}
+
+pub struct S7<T>(T);
+impl<T> S7<T> {
+    pub fn iter<U>(&self) -> std::slice::Iter<'static, (T, U)> {
+        todo!()
+    }
+}
+
+pub struct S8<T>(T);
+impl<T> S8<T> {
+    pub fn iter(&self) -> std::slice::Iter<'static, T> {
+        todo!()
+    }
+}
+
+// ===========================
+pub struct S9<T>(T);
+impl<T> S9<T> {
+    pub fn iter(&self) -> std::slice::Iter<'_, T> {
+        //~^ ERROR: `iter` method without an `IntoIterator` impl
+        todo!()
+    }
+    pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, T> {
+        //~^ ERROR: `iter_mut` method without an `IntoIterator` impl
+        todo!()
+    }
+}
+
+pub struct S10<T>(T);
+impl<T> S10<T> {
+    pub fn iter(&self) -> std::slice::Iter<'_, T> {
+        // Don't lint, there's an existing (wrong) IntoIterator impl
+        todo!()
+    }
+}
+
+impl<'a, T> IntoIterator for &'a S10<T> {
+    type Item = &'a String;
+    type IntoIter = std::slice::Iter<'a, String>;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
 
-        impl<'a, T> IntoIterator for &'a S<T> {
-            type Item = &'a String;
-            type IntoIter = std::slice::Iter<'a, String>;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
-    }
-    {
-        struct S<T>(T);
-        impl<T> S<T> {
-            pub fn iter_mut(&self) -> std::slice::IterMut<'_, T> {
-                // Don't lint, there's an existing (wrong) IntoIterator impl
-                todo!()
-            }
-        }
+pub struct S11<T>(T);
+impl<T> S11<T> {
+    pub fn iter_mut(&self) -> std::slice::IterMut<'_, T> {
+        // Don't lint, there's an existing (wrong) IntoIterator impl
+        todo!()
+    }
+}
+impl<'a, T> IntoIterator for &'a mut S11<T> {
+    type Item = &'a mut String;
+    type IntoIter = std::slice::IterMut<'a, String>;
+    fn into_iter(self) -> Self::IntoIter {
+        todo!()
+    }
+}
 
-        impl<'a, T> IntoIterator for &'a mut S<T> {
-            type Item = &'a mut String;
-            type IntoIter = std::slice::IterMut<'a, String>;
-            fn into_iter(self) -> Self::IntoIter {
-                todo!()
-            }
-        }
+// Private type not exported: don't lint
+struct S12;
+impl S12 {
+    fn iter(&self) -> std::slice::Iter<'_, u8> {
+        todo!()
     }
 }
+
+fn main() {}
diff --git a/tests/ui/iter_without_into_iter.stderr b/tests/ui/iter_without_into_iter.stderr
index 9d0b99415a50e..af5afd47bfc41 100644
--- a/tests/ui/iter_without_into_iter.stderr
+++ b/tests/ui/iter_without_into_iter.stderr
@@ -1,146 +1,146 @@
-error: `iter` method without an `IntoIterator` impl for `&S`
-  --> $DIR/iter_without_into_iter.rs:8:13
+error: `iter` method without an `IntoIterator` impl for `&S1`
+  --> $DIR/iter_without_into_iter.rs:6:5
    |
-LL | /             pub fn iter(&self) -> std::slice::Iter<'_, u8> {
+LL | /     pub fn iter(&self) -> std::slice::Iter<'_, u8> {
 LL | |
-LL | |                 [].iter()
-LL | |             }
-   | |_____________^
+LL | |         [].iter()
+LL | |     }
+   | |_____^
    |
    = note: `-D clippy::iter-without-into-iter` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::iter_without_into_iter)]`
-help: consider implementing `IntoIterator` for `&S`
+help: consider implementing `IntoIterator` for `&S1`
    |
-LL ~         
-LL + impl IntoIterator for &S {
+LL + 
+LL + impl IntoIterator for &S1 {
 LL +     type IntoIter = std::slice::Iter<'_, u8>;
-LL +     type Iter = &u8;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &u8;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter_mut` method without an `IntoIterator` impl for `&mut S`
-  --> $DIR/iter_without_into_iter.rs:12:13
+error: `iter_mut` method without an `IntoIterator` impl for `&mut S1`
+  --> $DIR/iter_without_into_iter.rs:10:5
    |
-LL | /             pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
+LL | /     pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
 LL | |
-LL | |                 [].iter_mut()
-LL | |             }
-   | |_____________^
+LL | |         [].iter_mut()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&mut S`
+help: consider implementing `IntoIterator` for `&mut S1`
    |
-LL ~         
-LL + impl IntoIterator for &mut S {
+LL + 
+LL + impl IntoIterator for &mut S1 {
 LL +     type IntoIter = std::slice::IterMut<'_, u8>;
-LL +     type Iter = &mut u8;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &mut u8;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter` method without an `IntoIterator` impl for `&S<'a>`
-  --> $DIR/iter_without_into_iter.rs:30:13
+error: `iter` method without an `IntoIterator` impl for `&S3<'a>`
+  --> $DIR/iter_without_into_iter.rs:26:5
    |
-LL | /             pub fn iter(&self) -> std::slice::Iter<'_, u8> {
+LL | /     pub fn iter(&self) -> std::slice::Iter<'_, u8> {
 LL | |
-LL | |                 self.0.iter()
-LL | |             }
-   | |_____________^
+LL | |         self.0.iter()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&S<'a>`
+help: consider implementing `IntoIterator` for `&S3<'a>`
    |
-LL ~         
-LL + impl IntoIterator for &S<'a> {
+LL + 
+LL + impl IntoIterator for &S3<'a> {
 LL +     type IntoIter = std::slice::Iter<'_, u8>;
-LL +     type Iter = &u8;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &u8;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter_mut` method without an `IntoIterator` impl for `&mut S<'a>`
-  --> $DIR/iter_without_into_iter.rs:34:13
+error: `iter_mut` method without an `IntoIterator` impl for `&mut S3<'a>`
+  --> $DIR/iter_without_into_iter.rs:30:5
    |
-LL | /             pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
+LL | /     pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, u8> {
 LL | |
-LL | |                 self.0.iter_mut()
-LL | |             }
-   | |_____________^
+LL | |         self.0.iter_mut()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&mut S<'a>`
+help: consider implementing `IntoIterator` for `&mut S3<'a>`
    |
-LL ~         
-LL + impl IntoIterator for &mut S<'a> {
+LL + 
+LL + impl IntoIterator for &mut S3<'a> {
 LL +     type IntoIter = std::slice::IterMut<'_, u8>;
-LL +     type Iter = &mut u8;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &mut u8;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter` method without an `IntoIterator` impl for `&S5<T>`
-  --> $DIR/iter_without_into_iter.rs:68:13
+error: `iter` method without an `IntoIterator` impl for `&S8<T>`
+  --> $DIR/iter_without_into_iter.rs:67:5
    |
-LL | /             pub fn iter(&self) -> std::slice::Iter<'static, T> {
-LL | |                 todo!()
-LL | |             }
-   | |_____________^
+LL | /     pub fn iter(&self) -> std::slice::Iter<'static, T> {
+LL | |         todo!()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&S5<T>`
+help: consider implementing `IntoIterator` for `&S8<T>`
    |
-LL ~         
-LL + impl IntoIterator for &S5<T> {
+LL + 
+LL + impl IntoIterator for &S8<T> {
 LL +     type IntoIter = std::slice::Iter<'static, T>;
-LL +     type Iter = &T;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &T;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter` method without an `IntoIterator` impl for `&S<T>`
-  --> $DIR/iter_without_into_iter.rs:76:13
+error: `iter` method without an `IntoIterator` impl for `&S9<T>`
+  --> $DIR/iter_without_into_iter.rs:75:5
    |
-LL | /             pub fn iter(&self) -> std::slice::Iter<'_, T> {
+LL | /     pub fn iter(&self) -> std::slice::Iter<'_, T> {
 LL | |
-LL | |                 todo!()
-LL | |             }
-   | |_____________^
+LL | |         todo!()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&S<T>`
+help: consider implementing `IntoIterator` for `&S9<T>`
    |
-LL ~         
-LL + impl IntoIterator for &S<T> {
+LL + 
+LL + impl IntoIterator for &S9<T> {
 LL +     type IntoIter = std::slice::Iter<'_, T>;
-LL +     type Iter = &T;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &T;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }
    |
 
-error: `iter_mut` method without an `IntoIterator` impl for `&mut S<T>`
-  --> $DIR/iter_without_into_iter.rs:80:13
+error: `iter_mut` method without an `IntoIterator` impl for `&mut S9<T>`
+  --> $DIR/iter_without_into_iter.rs:79:5
    |
-LL | /             pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, T> {
+LL | /     pub fn iter_mut(&mut self) -> std::slice::IterMut<'_, T> {
 LL | |
-LL | |                 todo!()
-LL | |             }
-   | |_____________^
+LL | |         todo!()
+LL | |     }
+   | |_____^
    |
-help: consider implementing `IntoIterator` for `&mut S<T>`
+help: consider implementing `IntoIterator` for `&mut S9<T>`
    |
-LL ~         
-LL + impl IntoIterator for &mut S<T> {
+LL + 
+LL + impl IntoIterator for &mut S9<T> {
 LL +     type IntoIter = std::slice::IterMut<'_, T>;
-LL +     type Iter = &mut T;
-LL +     fn into_iter() -> Self::IntoIter {
+LL +     type Item = &mut T;
+LL +     fn into_iter(self) -> Self::IntoIter {
 LL +         self.iter()
 LL +     }
 LL + }