diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 4f015ed1ce161..fbd5bc538e900 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -27,7 +27,7 @@ declare_lint! {
 
 declare_lint! {
     pub CONST_ERR,
-    Warn,
+    Deny,
     "constant evaluation detected erroneous expression"
 }
 
diff --git a/src/test/compile-fail/array_const_index-0.rs b/src/test/compile-fail/array_const_index-0.rs
index 9b9deb4ca8d9d..91007fcd63a28 100644
--- a/src/test/compile-fail/array_const_index-0.rs
+++ b/src/test/compile-fail/array_const_index-0.rs
@@ -10,9 +10,8 @@
 
 const A: &'static [i32] = &[];
 const B: i32 = (&A)[1];
-//~^ ERROR constant evaluation error
-//~| index out of bounds: the len is 0 but the index is 1
-//~| WARN this constant cannot be used
+//~^ index out of bounds: the len is 0 but the index is 1
+//~| ERROR this constant cannot be used
 
 fn main() {
     let _ = B;
diff --git a/src/test/compile-fail/array_const_index-1.rs b/src/test/compile-fail/array_const_index-1.rs
index 46feb20cf11dd..66739d308a70f 100644
--- a/src/test/compile-fail/array_const_index-1.rs
+++ b/src/test/compile-fail/array_const_index-1.rs
@@ -10,9 +10,8 @@
 
 const A: [i32; 0] = [];
 const B: i32 = A[1];
-//~^ ERROR constant evaluation error
-//~| index out of bounds: the len is 0 but the index is 1
-//~| WARN this constant cannot be used
+//~^ index out of bounds: the len is 0 but the index is 1
+//~| ERROR this constant cannot be used
 
 fn main() {
     let _ = B;
diff --git a/src/test/compile-fail/const-slice-oob.rs b/src/test/compile-fail/const-slice-oob.rs
index 7da5a2f17eaf9..6d51ff3099809 100644
--- a/src/test/compile-fail/const-slice-oob.rs
+++ b/src/test/compile-fail/const-slice-oob.rs
@@ -12,9 +12,8 @@
 
 const FOO: &'static[u32] = &[1, 2, 3];
 const BAR: u32 = FOO[5];
-//~^ ERROR constant evaluation error [E0080]
-//~| index out of bounds: the len is 3 but the index is 5
-//~| WARN this constant cannot be used
+//~^ index out of bounds: the len is 3 but the index is 5
+//~| ERROR this constant cannot be used
 
 fn main() {
     let _ = BAR;
diff --git a/src/test/compile-fail/eval-enum.rs b/src/test/compile-fail/eval-enum.rs
index 49f76c532df54..7315616860293 100644
--- a/src/test/compile-fail/eval-enum.rs
+++ b/src/test/compile-fail/eval-enum.rs
@@ -12,11 +12,11 @@ enum Test {
     DivZero = 1/0,
     //~^ attempt to divide by zero
     //~| ERROR constant evaluation error
-    //~| WARN constant evaluation error
+    //~| ERROR constant evaluation error
     RemZero = 1%0,
     //~^ attempt to calculate the remainder with a divisor of zero
     //~| ERROR constant evaluation error
-    //~| WARN constant evaluation error
+    //~| ERROR constant evaluation error
 }
 
 fn main() {}
diff --git a/src/test/incremental/warnings-reemitted.rs b/src/test/incremental/warnings-reemitted.rs
index d50ffff5c1e14..1ea436d8ad192 100644
--- a/src/test/incremental/warnings-reemitted.rs
+++ b/src/test/incremental/warnings-reemitted.rs
@@ -13,6 +13,7 @@
 // compile-pass
 
 #![allow(warnings)]
+#![warn(const_err)]
 
 fn main() {
     255u8 + 1; //~ WARNING this expression will panic at run-time
diff --git a/src/test/run-fail/overflowing-add.rs b/src/test/run-fail/overflowing-add.rs
index 250f0726dc9d6..584701410ef83 100644
--- a/src/test/run-fail/overflowing-add.rs
+++ b/src/test/run-fail/overflowing-add.rs
@@ -11,6 +11,8 @@
 // error-pattern:thread 'main' panicked at 'attempt to add with overflow'
 // compile-flags: -C debug-assertions
 
+#![allow(const_err)]
+
 fn main() {
     let _x = 200u8 + 200u8 + 200u8;
 }
diff --git a/src/test/run-fail/overflowing-mul.rs b/src/test/run-fail/overflowing-mul.rs
index b47d0fc4136cc..5d6f59e02296b 100644
--- a/src/test/run-fail/overflowing-mul.rs
+++ b/src/test/run-fail/overflowing-mul.rs
@@ -11,6 +11,8 @@
 // error-pattern:thread 'main' panicked at 'attempt to multiply with overflow'
 // compile-flags: -C debug-assertions
 
+#![allow(const_err)]
+
 fn main() {
     let x = 200u8 * 4;
 }
diff --git a/src/test/run-fail/overflowing-neg.rs b/src/test/run-fail/overflowing-neg.rs
index 836d7e37319e9..e7c518f1286fb 100644
--- a/src/test/run-fail/overflowing-neg.rs
+++ b/src/test/run-fail/overflowing-neg.rs
@@ -11,6 +11,8 @@
 // error-pattern:thread 'main' panicked at 'attempt to negate with overflow'
 // compile-flags: -C debug-assertions
 
+#![allow(const_err)]
+
 fn main() {
     let _x = -std::i8::MIN;
 }
diff --git a/src/test/run-fail/overflowing-sub.rs b/src/test/run-fail/overflowing-sub.rs
index f94cb31b16884..404921a1af552 100644
--- a/src/test/run-fail/overflowing-sub.rs
+++ b/src/test/run-fail/overflowing-sub.rs
@@ -11,6 +11,8 @@
 // error-pattern:thread 'main' panicked at 'attempt to subtract with overflow'
 // compile-flags: -C debug-assertions
 
+#![allow(const_err)]
+
 fn main() {
     let _x = 42u8 - (42u8 + 1);
 }
diff --git a/src/test/ui/const-eval-overflow-2.rs b/src/test/ui/const-eval-overflow-2.rs
index 885edb55ed86c..63f33cafaf827 100644
--- a/src/test/ui/const-eval-overflow-2.rs
+++ b/src/test/ui/const-eval-overflow-2.rs
@@ -11,7 +11,7 @@
 // Evaluation of constants in refutable patterns goes through
 // different compiler control-flow paths.
 
-#![allow(unused_imports, warnings)]
+#![allow(unused_imports, warnings, const_err)]
 
 use std::fmt;
 use std::{i8, i16, i32, i64, isize};
diff --git a/src/test/ui/const-eval-overflow-4.rs b/src/test/ui/const-eval-overflow-4.rs
index 24e178152eef0..ed14036b0b4cb 100644
--- a/src/test/ui/const-eval-overflow-4.rs
+++ b/src/test/ui/const-eval-overflow-4.rs
@@ -22,7 +22,7 @@ use std::{u8, u16, u32, u64, usize};
 const A_I8_T
     : [u32; (i8::MAX as i8 + 1i8) as usize]
     //~^ ERROR E0080
-    //~| WARN attempt to add with overflow
+    //~| ERROR attempt to add with overflow
     = [0; (i8::MAX as usize) + 1];
 
 fn main() {
diff --git a/src/test/ui/const-eval-overflow-4.stderr b/src/test/ui/const-eval-overflow-4.stderr
index db0a6fc820446..fc4762f0554f7 100644
--- a/src/test/ui/const-eval-overflow-4.stderr
+++ b/src/test/ui/const-eval-overflow-4.stderr
@@ -1,10 +1,10 @@
-warning: attempt to add with overflow
+error: attempt to add with overflow
   --> $DIR/const-eval-overflow-4.rs:23:13
    |
 LL |     : [u32; (i8::MAX as i8 + 1i8) as usize]
    |             ^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(const_err)] on by default
+   = note: #[deny(const_err)] on by default
 
 error[E0080]: constant evaluation error
   --> $DIR/const-eval-overflow-4.rs:23:13
@@ -12,6 +12,6 @@ error[E0080]: constant evaluation error
 LL |     : [u32; (i8::MAX as i8 + 1i8) as usize]
    |             ^^^^^^^^^^^^^^^^^^^^^ attempt to add with overflow
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/const-eval/conditional_array_execution.rs b/src/test/ui/const-eval/conditional_array_execution.rs
index dbddee862e022..8952a8386d7b8 100644
--- a/src/test/ui/const-eval/conditional_array_execution.rs
+++ b/src/test/ui/const-eval/conditional_array_execution.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // compile-pass
+#![warn(const_err)]
 
 const X: u32 = 5;
 const Y: u32 = 6;
diff --git a/src/test/ui/const-eval/conditional_array_execution.stderr b/src/test/ui/const-eval/conditional_array_execution.stderr
index 713b1b36c08b1..5cf73b9fad66d 100644
--- a/src/test/ui/const-eval/conditional_array_execution.stderr
+++ b/src/test/ui/const-eval/conditional_array_execution.stderr
@@ -1,19 +1,23 @@
 warning: attempt to subtract with overflow
-  --> $DIR/conditional_array_execution.rs:15:19
+  --> $DIR/conditional_array_execution.rs:16:19
    |
 LL | const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
    |                   ^^^^^
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/conditional_array_execution.rs:12:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: this constant cannot be used
-  --> $DIR/conditional_array_execution.rs:15:1
+  --> $DIR/conditional_array_execution.rs:16:1
    |
 LL | const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempt to subtract with overflow
 
 warning: constant evaluation error
-  --> $DIR/conditional_array_execution.rs:20:20
+  --> $DIR/conditional_array_execution.rs:21:20
    |
 LL |     println!("{}", FOO);
    |                    ^^^ referenced constant has errors
diff --git a/src/test/ui/const-eval/issue-43197.rs b/src/test/ui/const-eval/issue-43197.rs
index 097fba4d3c450..7ec100e411b36 100644
--- a/src/test/ui/const-eval/issue-43197.rs
+++ b/src/test/ui/const-eval/issue-43197.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // compile-pass
+#![warn(const_err)]
 
 #![feature(const_fn)]
 
diff --git a/src/test/ui/const-eval/issue-43197.stderr b/src/test/ui/const-eval/issue-43197.stderr
index a22e8016296c4..d0e13d5657e75 100644
--- a/src/test/ui/const-eval/issue-43197.stderr
+++ b/src/test/ui/const-eval/issue-43197.stderr
@@ -1,37 +1,41 @@
 warning: attempt to subtract with overflow
-  --> $DIR/issue-43197.rs:20:20
+  --> $DIR/issue-43197.rs:21:20
    |
 LL |     const X: u32 = 0-1;
    |                    ^^^
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/issue-43197.rs:12:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: this constant cannot be used
-  --> $DIR/issue-43197.rs:20:5
+  --> $DIR/issue-43197.rs:21:5
    |
 LL |     const X: u32 = 0-1;
    |     ^^^^^^^^^^^^^^^^^^^ attempt to subtract with overflow
 
 warning: attempt to subtract with overflow
-  --> $DIR/issue-43197.rs:23:24
+  --> $DIR/issue-43197.rs:24:24
    |
 LL |     const Y: u32 = foo(0-1);
    |                        ^^^
 
 warning: this constant cannot be used
-  --> $DIR/issue-43197.rs:23:5
+  --> $DIR/issue-43197.rs:24:5
    |
 LL |     const Y: u32 = foo(0-1);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ attempt to subtract with overflow
 
 warning: constant evaluation error
-  --> $DIR/issue-43197.rs:26:23
+  --> $DIR/issue-43197.rs:27:23
    |
 LL |     println!("{} {}", X, Y);
    |                       ^ referenced constant has errors
 
 warning: constant evaluation error
-  --> $DIR/issue-43197.rs:26:26
+  --> $DIR/issue-43197.rs:27:26
    |
 LL |     println!("{} {}", X, Y);
    |                          ^ referenced constant has errors
diff --git a/src/test/ui/const-eval/issue-44578.rs b/src/test/ui/const-eval/issue-44578.rs
index 765113cfbb9e2..4133a8864f619 100644
--- a/src/test/ui/const-eval/issue-44578.rs
+++ b/src/test/ui/const-eval/issue-44578.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // compile-pass
+#![warn(const_err)]
 
 trait Foo {
     const AMT: usize;
diff --git a/src/test/ui/const-eval/issue-44578.stderr b/src/test/ui/const-eval/issue-44578.stderr
index 01c6fa3623f8d..ce6ff86610aa5 100644
--- a/src/test/ui/const-eval/issue-44578.stderr
+++ b/src/test/ui/const-eval/issue-44578.stderr
@@ -1,13 +1,17 @@
 warning: constant evaluation error
-  --> $DIR/issue-44578.rs:35:20
+  --> $DIR/issue-44578.rs:36:20
    |
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT); //~ WARN const_err
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^ referenced constant has errors
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/issue-44578.rs:12:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: constant evaluation error
-  --> $DIR/issue-44578.rs:35:20
+  --> $DIR/issue-44578.rs:36:20
    |
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT); //~ WARN const_err
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^ referenced constant has errors
diff --git a/src/test/ui/const-eval/promoted_errors.rs b/src/test/ui/const-eval/promoted_errors.rs
index dc30c7f9cce04..7385860abae28 100644
--- a/src/test/ui/const-eval/promoted_errors.rs
+++ b/src/test/ui/const-eval/promoted_errors.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![warn(const_err)]
+
 // compile-pass
 // compile-flags: -O
 fn main() {
diff --git a/src/test/ui/const-eval/promoted_errors.stderr b/src/test/ui/const-eval/promoted_errors.stderr
index 7761f192fdb70..8e9a0ea43a43b 100644
--- a/src/test/ui/const-eval/promoted_errors.stderr
+++ b/src/test/ui/const-eval/promoted_errors.stderr
@@ -1,49 +1,53 @@
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:14:20
+  --> $DIR/promoted_errors.rs:16:20
    |
 LL |     println!("{}", 0u32 - 1);
    |                    ^^^^^^^^ attempt to subtract with overflow
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/promoted_errors.rs:11:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:14:20
+  --> $DIR/promoted_errors.rs:16:20
    |
 LL |     println!("{}", 0u32 - 1);
    |                    ^^^^^^^^ attempt to subtract with overflow
 
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:17:14
+  --> $DIR/promoted_errors.rs:19:14
    |
 LL |     let _x = 0u32 - 1;
    |              ^^^^^^^^ attempt to subtract with overflow
 
 warning: attempt to divide by zero
-  --> $DIR/promoted_errors.rs:19:20
+  --> $DIR/promoted_errors.rs:21:20
    |
 LL |     println!("{}", 1/(1-1));
    |                    ^^^^^^^
 
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:19:20
+  --> $DIR/promoted_errors.rs:21:20
    |
 LL |     println!("{}", 1/(1-1));
    |                    ^^^^^^^ attempt to divide by zero
 
 warning: attempt to divide by zero
-  --> $DIR/promoted_errors.rs:22:14
+  --> $DIR/promoted_errors.rs:24:14
    |
 LL |     let _x = 1/(1-1);
    |              ^^^^^^^
 
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:22:14
+  --> $DIR/promoted_errors.rs:24:14
    |
 LL |     let _x = 1/(1-1);
    |              ^^^^^^^ attempt to divide by zero
 
 warning: constant evaluation error
-  --> $DIR/promoted_errors.rs:25:20
+  --> $DIR/promoted_errors.rs:27:20
    |
 LL |     println!("{}", 1/(false as u32));
    |                    ^^^^^^^^^^^^^^^^ attempt to divide by zero
diff --git a/src/test/ui/const-eval/pub_const_err.rs b/src/test/ui/const-eval/pub_const_err.rs
index c6bf07649af38..ef8fdb33d748a 100644
--- a/src/test/ui/const-eval/pub_const_err.rs
+++ b/src/test/ui/const-eval/pub_const_err.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // compile-pass
+#![warn(const_err)]
 
 #![crate_type = "lib"]
 
diff --git a/src/test/ui/const-eval/pub_const_err.stderr b/src/test/ui/const-eval/pub_const_err.stderr
index 2981ac20cd981..068825f1cd310 100644
--- a/src/test/ui/const-eval/pub_const_err.stderr
+++ b/src/test/ui/const-eval/pub_const_err.stderr
@@ -1,25 +1,29 @@
 warning: attempt to subtract with overflow
-  --> $DIR/pub_const_err.rs:15:20
+  --> $DIR/pub_const_err.rs:16:20
    |
 LL | pub const Z: u32 = 0 - 1;
    |                    ^^^^^
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/pub_const_err.rs:12:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: this constant cannot be used
-  --> $DIR/pub_const_err.rs:15:1
+  --> $DIR/pub_const_err.rs:16:1
    |
 LL | pub const Z: u32 = 0 - 1;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^ attempt to subtract with overflow
 
 warning: attempt to subtract with overflow
-  --> $DIR/pub_const_err.rs:19:22
+  --> $DIR/pub_const_err.rs:20:22
    |
 LL | pub type Foo = [i32; 0 - 1];
    |                      ^^^^^
 
 warning: this array length cannot be used
-  --> $DIR/pub_const_err.rs:19:22
+  --> $DIR/pub_const_err.rs:20:22
    |
 LL | pub type Foo = [i32; 0 - 1];
    |                      ^^^^^ attempt to subtract with overflow
diff --git a/src/test/ui/const-eval/pub_const_err_bin.rs b/src/test/ui/const-eval/pub_const_err_bin.rs
index d87cb7ed77079..f65da1d8674a2 100644
--- a/src/test/ui/const-eval/pub_const_err_bin.rs
+++ b/src/test/ui/const-eval/pub_const_err_bin.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // compile-pass
+#![warn(const_err)]
 
 pub const Z: u32 = 0 - 1;
 //~^ WARN attempt to subtract with overflow
diff --git a/src/test/ui/const-eval/pub_const_err_bin.stderr b/src/test/ui/const-eval/pub_const_err_bin.stderr
index 3e8966d854bf0..dcb8125fc55bc 100644
--- a/src/test/ui/const-eval/pub_const_err_bin.stderr
+++ b/src/test/ui/const-eval/pub_const_err_bin.stderr
@@ -1,25 +1,29 @@
 warning: attempt to subtract with overflow
-  --> $DIR/pub_const_err_bin.rs:13:20
+  --> $DIR/pub_const_err_bin.rs:14:20
    |
 LL | pub const Z: u32 = 0 - 1;
    |                    ^^^^^
    |
-   = note: #[warn(const_err)] on by default
+note: lint level defined here
+  --> $DIR/pub_const_err_bin.rs:12:9
+   |
+LL | #![warn(const_err)]
+   |         ^^^^^^^^^
 
 warning: this constant cannot be used
-  --> $DIR/pub_const_err_bin.rs:13:1
+  --> $DIR/pub_const_err_bin.rs:14:1
    |
 LL | pub const Z: u32 = 0 - 1;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^ attempt to subtract with overflow
 
 warning: attempt to subtract with overflow
-  --> $DIR/pub_const_err_bin.rs:17:22
+  --> $DIR/pub_const_err_bin.rs:18:22
    |
 LL | pub type Foo = [i32; 0 - 1];
    |                      ^^^^^
 
 warning: this array length cannot be used
-  --> $DIR/pub_const_err_bin.rs:17:22
+  --> $DIR/pub_const_err_bin.rs:18:22
    |
 LL | pub type Foo = [i32; 0 - 1];
    |                      ^^^^^ attempt to subtract with overflow
diff --git a/src/test/ui/const-len-underflow-separate-spans.rs b/src/test/ui/const-len-underflow-separate-spans.rs
index ee07dabab1fc8..453e332a903c7 100644
--- a/src/test/ui/const-len-underflow-separate-spans.rs
+++ b/src/test/ui/const-len-underflow-separate-spans.rs
@@ -16,7 +16,7 @@ const ONE: usize = 1;
 const TWO: usize = 2;
 const LEN: usize = ONE - TWO;
 //~^ ERROR E0080
-//~| WARN attempt to subtract with overflow
+//~| ERROR attempt to subtract with overflow
 
 fn main() {
     let a: [i8; LEN] = unimplemented!();
diff --git a/src/test/ui/const-len-underflow-separate-spans.stderr b/src/test/ui/const-len-underflow-separate-spans.stderr
index 8d737dbfc0857..48ff7a81c24ee 100644
--- a/src/test/ui/const-len-underflow-separate-spans.stderr
+++ b/src/test/ui/const-len-underflow-separate-spans.stderr
@@ -1,10 +1,10 @@
-warning: attempt to subtract with overflow
+error: attempt to subtract with overflow
   --> $DIR/const-len-underflow-separate-spans.rs:17:20
    |
 LL | const LEN: usize = ONE - TWO;
    |                    ^^^^^^^^^
    |
-   = note: #[warn(const_err)] on by default
+   = note: #[deny(const_err)] on by default
 
 error[E0080]: constant evaluation error
   --> $DIR/const-len-underflow-separate-spans.rs:17:20
@@ -18,6 +18,6 @@ error[E0080]: constant evaluation error
 LL |     let a: [i8; LEN] = unimplemented!();
    |                 ^^^ referenced constant has errors
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/error-codes/E0080.stderr b/src/test/ui/error-codes/E0080.stderr
index 5e401bd6c79da..25ec5c458312d 100644
--- a/src/test/ui/error-codes/E0080.stderr
+++ b/src/test/ui/error-codes/E0080.stderr
@@ -12,15 +12,15 @@ error[E0080]: constant evaluation error
 LL |     X = (1 << 500), //~ ERROR E0080
    |         ^^^^^^^^^^ attempt to shift left with overflow
 
-warning: attempt to divide by zero
+error: attempt to divide by zero
   --> $DIR/E0080.rs:14:9
    |
 LL |     Y = (1 / 0) //~ ERROR E0080
    |         ^^^^^^^
    |
-   = note: #[warn(const_err)] on by default
+   = note: #[deny(const_err)] on by default
 
-warning: constant evaluation error
+error: constant evaluation error
   --> $DIR/E0080.rs:14:9
    |
 LL |     Y = (1 / 0) //~ ERROR E0080
@@ -32,6 +32,6 @@ error[E0080]: constant evaluation error
 LL |     Y = (1 / 0) //~ ERROR E0080
    |         ^^^^^^^ attempt to divide by zero
 
-error: aborting due to 3 previous errors
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0080`.