diff --git a/src/test/ui/consts/const-eval/ub-nonnull.32bit.stderr b/src/test/ui/consts/const-eval/ub-nonnull.32bit.stderr
index dbd05b8f424..b24e0cc37aa 100644
--- a/src/test/ui/consts/const-eval/ub-nonnull.32bit.stderr
+++ b/src/test/ui/consts/const-eval/ub-nonnull.32bit.stderr
@@ -65,6 +65,17 @@ LL | const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) };
                14 00 00 00                                     │ ....
            }
 
-error: aborting due to 7 previous errors
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/ub-nonnull.rs:50:1
+   |
+LL | const NULL_FAT_PTR: NonNull<dyn Send> = unsafe {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: 8, align: 4) {
+               00 00 00 00 ╾─alloc26─╼                         │ ....╾──╼
+           }
+
+error: aborting due to 8 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/ub-nonnull.64bit.stderr b/src/test/ui/consts/const-eval/ub-nonnull.64bit.stderr
index 5a1ac09bd35..92b8d017c0b 100644
--- a/src/test/ui/consts/const-eval/ub-nonnull.64bit.stderr
+++ b/src/test/ui/consts/const-eval/ub-nonnull.64bit.stderr
@@ -65,6 +65,17 @@ LL | const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) };
                14 00 00 00                                     │ ....
            }
 
-error: aborting due to 7 previous errors
+error[E0080]: it is undefined behavior to use this value
+  --> $DIR/ub-nonnull.rs:50:1
+   |
+LL | const NULL_FAT_PTR: NonNull<dyn Send> = unsafe {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
+   = note: the raw bytes of the constant (size: 16, align: 8) {
+               00 00 00 00 00 00 00 00 ╾───────alloc26───────╼ │ ........╾──────╼
+           }
+
+error: aborting due to 8 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/ub-nonnull.rs b/src/test/ui/consts/const-eval/ub-nonnull.rs
index d22a99cd01e..49092582267 100644
--- a/src/test/ui/consts/const-eval/ub-nonnull.rs
+++ b/src/test/ui/consts/const-eval/ub-nonnull.rs
@@ -1,5 +1,5 @@
 // stderr-per-bitwidth
-#![feature(rustc_attrs)]
+#![feature(rustc_attrs, ptr_metadata)]
 #![allow(invalid_value)] // make sure we cannot allow away the errors tested here
 
 use std::mem;
@@ -47,4 +47,11 @@ union MaybeUninit<T: Copy> {
 const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) };
 //~^ ERROR it is undefined behavior to use this value
 
+const NULL_FAT_PTR: NonNull<dyn Send> = unsafe {
+//~^ ERROR it is undefined behavior to use this value
+    let x: &dyn Send = &42;
+    let meta = std::ptr::metadata(x);
+    mem::transmute((0_usize, meta))
+};
+
 fn main() {}