diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
index bbcc7c699e0..0bb2566fd4c 100644
--- a/library/core/src/ptr/mut_ptr.rs
+++ b/library/core/src/ptr/mut_ptr.rs
@@ -80,10 +80,14 @@ impl<T: ?Sized> *mut T {
     #[unstable(feature = "set_ptr_value", issue = "75091")]
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[inline]
-    pub fn with_metadata_of<U>(self, mut val: *mut U) -> *mut U
+    pub fn with_metadata_of<U>(self, val: *const U) -> *mut U
     where
         U: ?Sized,
     {
+        // Prepare in the type system that we will replace the pointer value with a mutable
+        // pointer, taking the mutable provenance from the `self` pointer.
+        let mut val = val as *mut U;
+        // Pointer to the pointer value within the value.
         let target = &mut val as *mut *mut U as *mut *mut u8;
         // SAFETY: In case of a thin pointer, this operations is identical
         // to a simple assignment. In case of a fat pointer, with the current