diff --git a/src/type-coercions.md b/src/type-coercions.md
index ae60c3df96..e52182767a 100644
--- a/src/type-coercions.md
+++ b/src/type-coercions.md
@@ -194,7 +194,7 @@ r[coerce.unsized.composite]
     * T is not part of the type of any other fields.
 
 r[coerce.unsized.pointer]
-Additionally, a type `Foo<T>` can implement `CoerceUnsized<Foo<U>>` when `T` implements `Unsize<U>` or `CoerceUnsized<Foo<U>>`. This allows it to provide an unsized coercion to `Foo<U>`.
+Additionally, a type `Foo<T>` can implement `CoerceUnsized<Foo<U>>` if there exists exactly one non-`PhantomData` field which depends on the changed generic parameters for which `Field<T>: CoerceUnsized<Field<U>>` holds. This allows it to provide an unsized coercion to `Foo<U>`.
 
 > [!NOTE]
 > While the definition of the unsized coercions and their implementation has been stabilized, the traits themselves are not yet stable and therefore can't be used directly in stable Rust.