diff --git a/clippy_lints/src/new_without_default.rs b/clippy_lints/src/new_without_default.rs
index b598a390005b..ab7b09c48a7f 100644
--- a/clippy_lints/src/new_without_default.rs
+++ b/clippy_lints/src/new_without_default.rs
@@ -94,7 +94,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                             return;
                         }
                         if sig.decl.inputs.is_empty()
-                            && cx.effective_visibilities.is_reachable(impl_item.owner_id.def_id)
+                            && cx.effective_visibilities.is_exported(impl_item.owner_id.def_id)
                             && let self_ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
                             && self_ty == return_ty(cx, impl_item.owner_id)
                             && let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default)
diff --git a/tests/ui/new_without_default.fixed b/tests/ui/new_without_default.fixed
index 277c335cd885..b5558cd3086c 100644
--- a/tests/ui/new_without_default.fixed
+++ b/tests/ui/new_without_default.fixed
@@ -322,3 +322,23 @@ where
         Self { _kv: None }
     }
 }
+
+mod issue15778 {
+    pub struct Foo(Vec<i32>);
+
+    impl Foo {
+        pub fn new() -> Self {
+            Self(Vec::new())
+        }
+    }
+
+    impl<'a> IntoIterator for &'a Foo {
+        type Item = &'a i32;
+
+        type IntoIter = std::slice::Iter<'a, i32>;
+
+        fn into_iter(self) -> Self::IntoIter {
+            self.0.as_slice().iter()
+        }
+    }
+}
diff --git a/tests/ui/new_without_default.rs b/tests/ui/new_without_default.rs
index f2844897c93d..be598c81718f 100644
--- a/tests/ui/new_without_default.rs
+++ b/tests/ui/new_without_default.rs
@@ -265,3 +265,23 @@ where
         Self { _kv: None }
     }
 }
+
+mod issue15778 {
+    pub struct Foo(Vec<i32>);
+
+    impl Foo {
+        pub fn new() -> Self {
+            Self(Vec::new())
+        }
+    }
+
+    impl<'a> IntoIterator for &'a Foo {
+        type Item = &'a i32;
+
+        type IntoIter = std::slice::Iter<'a, i32>;
+
+        fn into_iter(self) -> Self::IntoIter {
+            self.0.as_slice().iter()
+        }
+    }
+}