diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index 763bd4fc391..904847d0929 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -210,7 +210,7 @@ declare_features! (
     /// Allows the `multiple_supertrait_upcastable` lint.
     (unstable, multiple_supertrait_upcastable, "1.69.0", None),
     /// Allow negative trait bounds. This is an internal-only feature for testing the trait solver!
-    (incomplete, negative_bounds, "1.71.0", None),
+    (internal, negative_bounds, "1.71.0", None),
     /// Allows using `#[omit_gdb_pretty_printer_section]`.
     (internal, omit_gdb_pretty_printer_section, "1.5.0", None),
     /// Allows using `#[prelude_import]` on glob `use` items.
diff --git a/tests/ui/traits/negative-bounds/associated-constraints.rs b/tests/ui/traits/negative-bounds/associated-constraints.rs
index bc1a0ef1708..23ca2e41f34 100644
--- a/tests/ui/traits/negative-bounds/associated-constraints.rs
+++ b/tests/ui/traits/negative-bounds/associated-constraints.rs
@@ -1,5 +1,4 @@
 #![feature(negative_bounds, associated_type_bounds)]
-//~^ WARN the feature `negative_bounds` is incomplete and may not be safe to use and/or cause compiler crashes
 
 trait Trait {
     type Assoc;
diff --git a/tests/ui/traits/negative-bounds/associated-constraints.stderr b/tests/ui/traits/negative-bounds/associated-constraints.stderr
index 335ac7e5ad9..eae0ba4e6e4 100644
--- a/tests/ui/traits/negative-bounds/associated-constraints.stderr
+++ b/tests/ui/traits/negative-bounds/associated-constraints.stderr
@@ -1,34 +1,25 @@
 error: associated type constraints not allowed on negative bounds
-  --> $DIR/associated-constraints.rs:8:19
+  --> $DIR/associated-constraints.rs:7:19
    |
 LL | fn test<T: !Trait<Assoc = i32>>() {}
    |                   ^^^^^^^^^^^
 
 error: associated type constraints not allowed on negative bounds
-  --> $DIR/associated-constraints.rs:11:31
+  --> $DIR/associated-constraints.rs:10:31
    |
 LL | fn test2<T>() where T: !Trait<Assoc = i32> {}
    |                               ^^^^^^^^^^^
 
 error: associated type constraints not allowed on negative bounds
-  --> $DIR/associated-constraints.rs:14:20
+  --> $DIR/associated-constraints.rs:13:20
    |
 LL | fn test3<T: !Trait<Assoc: Send>>() {}
    |                    ^^^^^^^^^^^
 
 error: associated type constraints not allowed on negative bounds
-  --> $DIR/associated-constraints.rs:17:31
+  --> $DIR/associated-constraints.rs:16:31
    |
 LL | fn test4<T>() where T: !Trait<Assoc: Send> {}
    |                               ^^^^^^^^^^^
 
-warning: the feature `negative_bounds` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/associated-constraints.rs:1:12
-   |
-LL | #![feature(negative_bounds, associated_type_bounds)]
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: `#[warn(incomplete_features)]` on by default
-
-error: aborting due to 4 previous errors; 1 warning emitted
-
+error: aborting due to 4 previous errors
diff --git a/tests/ui/traits/negative-bounds/simple.rs b/tests/ui/traits/negative-bounds/simple.rs
index f6d1d5169c4..a2febf353f6 100644
--- a/tests/ui/traits/negative-bounds/simple.rs
+++ b/tests/ui/traits/negative-bounds/simple.rs
@@ -1,5 +1,4 @@
 #![feature(negative_bounds, negative_impls)]
-//~^ WARN the feature `negative_bounds` is incomplete and may not be safe to use and/or cause compiler crashes
 
 fn not_copy<T: !Copy>() {}
 
diff --git a/tests/ui/traits/negative-bounds/simple.stderr b/tests/ui/traits/negative-bounds/simple.stderr
index a3cab41a2ce..6d750739e19 100644
--- a/tests/ui/traits/negative-bounds/simple.stderr
+++ b/tests/ui/traits/negative-bounds/simple.stderr
@@ -1,44 +1,36 @@
-warning: the feature `negative_bounds` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/simple.rs:1:12
-   |
-LL | #![feature(negative_bounds, negative_impls)]
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: `#[warn(incomplete_features)]` on by default
-
 error[E0277]: the trait bound `T: !Copy` is not satisfied
-  --> $DIR/simple.rs:11:16
+  --> $DIR/simple.rs:10:16
    |
 LL |     not_copy::<T>();
    |                ^ the trait `!Copy` is not implemented for `T`
    |
 note: required by a bound in `not_copy`
-  --> $DIR/simple.rs:4:16
+  --> $DIR/simple.rs:3:16
    |
 LL | fn not_copy<T: !Copy>() {}
    |                ^^^^^ required by this bound in `not_copy`
 
 error[E0277]: the trait bound `T: !Copy` is not satisfied
-  --> $DIR/simple.rs:16:16
+  --> $DIR/simple.rs:15:16
    |
 LL |     not_copy::<T>();
    |                ^ the trait `!Copy` is not implemented for `T`
    |
 note: required by a bound in `not_copy`
-  --> $DIR/simple.rs:4:16
+  --> $DIR/simple.rs:3:16
    |
 LL | fn not_copy<T: !Copy>() {}
    |                ^^^^^ required by this bound in `not_copy`
 
 error[E0277]: the trait bound `Copyable: !Copy` is not satisfied
-  --> $DIR/simple.rs:31:16
+  --> $DIR/simple.rs:30:16
    |
 LL |     not_copy::<Copyable>();
    |                ^^^^^^^^ the trait `!Copy` is not implemented for `Copyable`
    |
    = help: the trait `Copy` is implemented for `Copyable`
 note: required by a bound in `not_copy`
-  --> $DIR/simple.rs:4:16
+  --> $DIR/simple.rs:3:16
    |
 LL | fn not_copy<T: !Copy>() {}
    |                ^^^^^ required by this bound in `not_copy`
@@ -49,13 +41,13 @@ LL | struct Copyable;
    |
 
 error[E0277]: the trait bound `NotNecessarilyCopyable: !Copy` is not satisfied
-  --> $DIR/simple.rs:38:16
+  --> $DIR/simple.rs:37:16
    |
 LL |     not_copy::<NotNecessarilyCopyable>();
    |                ^^^^^^^^^^^^^^^^^^^^^^ the trait `!Copy` is not implemented for `NotNecessarilyCopyable`
    |
 note: required by a bound in `not_copy`
-  --> $DIR/simple.rs:4:16
+  --> $DIR/simple.rs:3:16
    |
 LL | fn not_copy<T: !Copy>() {}
    |                ^^^^^ required by this bound in `not_copy`
@@ -65,6 +57,6 @@ LL + #[derive(Copy)]
 LL | struct NotNecessarilyCopyable;
    |
 
-error: aborting due to 4 previous errors; 1 warning emitted
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/traits/negative-bounds/supertrait.rs b/tests/ui/traits/negative-bounds/supertrait.rs
index df0884b8b9f..a66bc4a60a0 100644
--- a/tests/ui/traits/negative-bounds/supertrait.rs
+++ b/tests/ui/traits/negative-bounds/supertrait.rs
@@ -1,7 +1,6 @@
 // check-pass
 
 #![feature(negative_bounds)]
-//~^ WARN the feature `negative_bounds` is incomplete
 
 trait A: !B {}
 trait B: !A {}
diff --git a/tests/ui/traits/negative-bounds/supertrait.stderr b/tests/ui/traits/negative-bounds/supertrait.stderr
deleted file mode 100644
index f44753b624e..00000000000
--- a/tests/ui/traits/negative-bounds/supertrait.stderr
+++ /dev/null
@@ -1,10 +0,0 @@
-warning: the feature `negative_bounds` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/supertrait.rs:3:12
-   |
-LL | #![feature(negative_bounds)]
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: `#[warn(incomplete_features)]` on by default
-
-warning: 1 warning emitted
-