diff --git a/src/test/ui/consts/miri_unleashed/mutable_const.rs b/src/test/ui/consts/miri_unleashed/mutable_const.rs
index 44b408494679..cf5e6d600258 100644
--- a/src/test/ui/consts/miri_unleashed/mutable_const.rs
+++ b/src/test/ui/consts/miri_unleashed/mutable_const.rs
@@ -12,9 +12,7 @@ const MUTABLE_BEHIND_RAW: *mut i32 = &UnsafeCell::new(42) as *const _ as *mut _;
 const MUTATING_BEHIND_RAW: () = {
     // Test that `MUTABLE_BEHIND_RAW` is actually immutable, by doing this at const time.
     unsafe {
-        *MUTABLE_BEHIND_RAW = 99 //~ WARN skipping const checks
-        //~^ ERROR any use of this value will cause an error
-        //~^^ tried to modify constant memory
+        *MUTABLE_BEHIND_RAW = 99 //~ ERROR constant contains unimplemented expression type
     }
 };
 
diff --git a/src/test/ui/consts/miri_unleashed/mutable_const.stderr b/src/test/ui/consts/miri_unleashed/mutable_const.stderr
index 757f0ffb59ff..1a18063625be 100644
--- a/src/test/ui/consts/miri_unleashed/mutable_const.stderr
+++ b/src/test/ui/consts/miri_unleashed/mutable_const.stderr
@@ -4,30 +4,12 @@ warning: skipping const checks
 LL | const MUTABLE_BEHIND_RAW: *mut i32 = &UnsafeCell::new(42) as *const _ as *mut _;
    |                                      ^^^^^^^^^^^^^^^^^^^^
 
-warning: skipping const checks
+error[E0019]: constant contains unimplemented expression type
   --> $DIR/mutable_const.rs:15:9
    |
 LL |         *MUTABLE_BEHIND_RAW = 99
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: any use of this value will cause an error
-  --> $DIR/mutable_const.rs:15:9
-   |
-LL | / const MUTATING_BEHIND_RAW: () = {
-LL | |     // Test that `MUTABLE_BEHIND_RAW` is actually immutable, by doing this at const time.
-LL | |     unsafe {
-LL | |         *MUTABLE_BEHIND_RAW = 99
-   | |         ^^^^^^^^^^^^^^^^^^^^^^^^ tried to modify constant memory
-...  |
-LL | |     }
-LL | | };
-   | |__-
-   |
-note: lint level defined here
-  --> $DIR/mutable_const.rs:4:9
-   |
-LL | #![deny(const_err)]
-   |         ^^^^^^^^^
-
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0019`.
diff --git a/src/test/ui/consts/miri_unleashed/mutable_references.rs b/src/test/ui/consts/miri_unleashed/mutable_references.rs
index 59dafcbf4d50..d95833e3071d 100644
--- a/src/test/ui/consts/miri_unleashed/mutable_references.rs
+++ b/src/test/ui/consts/miri_unleashed/mutable_references.rs
@@ -1,4 +1,5 @@
 // compile-flags: -Zunleash-the-miri-inside-of-you
+#![feature(const_mut_refs)]
 #![allow(const_err)]
 
 use std::cell::UnsafeCell;
@@ -6,15 +7,12 @@ use std::cell::UnsafeCell;
 // a test demonstrating what things we could allow with a smarter const qualification
 
 static FOO: &&mut u32 = &&mut 42;
-//~^ WARN: skipping const checks
 
 static BAR: &mut () = &mut ();
-//~^ WARN: skipping const checks
 
 struct Foo<T>(T);
 
 static BOO: &mut Foo<()> = &mut Foo(());
-//~^ WARN: skipping const checks
 
 struct Meh {
     x: &'static UnsafeCell<i32>,
@@ -28,7 +26,6 @@ static MEH: Meh = Meh {
 };
 
 static OH_YES: &mut i32 = &mut 42;
-//~^ WARN: skipping const checks
 
 fn main() {
     unsafe {
diff --git a/src/test/ui/consts/miri_unleashed/mutable_references.stderr b/src/test/ui/consts/miri_unleashed/mutable_references.stderr
index b9c0af33c39c..ce1f5f38dd99 100644
--- a/src/test/ui/consts/miri_unleashed/mutable_references.stderr
+++ b/src/test/ui/consts/miri_unleashed/mutable_references.stderr
@@ -1,35 +1,11 @@
 warning: skipping const checks
-  --> $DIR/mutable_references.rs:8:26
-   |
-LL | static FOO: &&mut u32 = &&mut 42;
-   |                          ^^^^^^^
-
-warning: skipping const checks
-  --> $DIR/mutable_references.rs:11:23
-   |
-LL | static BAR: &mut () = &mut ();
-   |                       ^^^^^^^
-
-warning: skipping const checks
-  --> $DIR/mutable_references.rs:16:28
-   |
-LL | static BOO: &mut Foo<()> = &mut Foo(());
-   |                            ^^^^^^^^^^^^
-
-warning: skipping const checks
-  --> $DIR/mutable_references.rs:26:8
+  --> $DIR/mutable_references.rs:24:8
    |
 LL |     x: &UnsafeCell::new(42),
    |        ^^^^^^^^^^^^^^^^^^^^
 
-warning: skipping const checks
-  --> $DIR/mutable_references.rs:30:27
-   |
-LL | static OH_YES: &mut i32 = &mut 42;
-   |                           ^^^^^^^
-
 error[E0594]: cannot assign to `*OH_YES`, as `OH_YES` is an immutable static item
-  --> $DIR/mutable_references.rs:37:5
+  --> $DIR/mutable_references.rs:34:5
    |
 LL |     *OH_YES = 99;
    |     ^^^^^^^^^^^^ cannot assign