diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index 535cb13276646..418270c621596 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -692,7 +692,6 @@ pub const INCOMPLETE_FEATURES: &[Symbol] = &[
     sym::repr128,
     sym::unsized_locals,
     sym::capture_disjoint_fields,
-    sym::const_generics_defaults,
     sym::inherent_associated_types,
     sym::type_alias_impl_trait,
     sym::native_link_modifiers,
diff --git a/src/test/ui/const-generics/defaults/const-param-as-default-value.rs b/src/test/ui/const-generics/defaults/const-param-as-default-value.rs
index 59ac261f44fd5..9779835d3150b 100644
--- a/src/test/ui/const-generics/defaults/const-param-as-default-value.rs
+++ b/src/test/ui/const-generics/defaults/const-param-as-default-value.rs
@@ -1,6 +1,5 @@
 // run-pass
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 struct Foo<const N: usize, const M: usize = N>([u8; N], [u8; M]);
 
 fn foo<const N: usize>() -> Foo<N> {
diff --git a/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs b/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs
index 3f534ca0308ba..dbcab77dcd2ee 100644
--- a/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs
+++ b/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs
@@ -1,6 +1,5 @@
 // run-pass
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 struct Foo<const N: usize, T = [u8; N]>(T);
 
 impl<const N: usize> Foo<N> {
diff --git a/src/test/ui/const-generics/defaults/default-param-wf-concrete.rs b/src/test/ui/const-generics/defaults/default-param-wf-concrete.rs
index 4bb56c6a1c08c..d4271adefd12a 100644
--- a/src/test/ui/const-generics/defaults/default-param-wf-concrete.rs
+++ b/src/test/ui/const-generics/defaults/default-param-wf-concrete.rs
@@ -1,5 +1,4 @@
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 struct Foo<const N: u8 = { 255 + 1 }>;
 //~^ ERROR evaluation of constant value failed
 fn main() {}
diff --git a/src/test/ui/const-generics/defaults/default-param-wf-concrete.stderr b/src/test/ui/const-generics/defaults/default-param-wf-concrete.stderr
index 8464ea98bf695..6fca9d31c0a99 100644
--- a/src/test/ui/const-generics/defaults/default-param-wf-concrete.stderr
+++ b/src/test/ui/const-generics/defaults/default-param-wf-concrete.stderr
@@ -1,5 +1,5 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/default-param-wf-concrete.rs:3:28
+  --> $DIR/default-param-wf-concrete.rs:2:28
    |
 LL | struct Foo<const N: u8 = { 255 + 1 }>;
    |                            ^^^^^^^ attempt to compute `u8::MAX + 1_u8`, which would overflow
diff --git a/src/test/ui/const-generics/defaults/pretty-printing-ast.rs b/src/test/ui/const-generics/defaults/pretty-printing-ast.rs
index 7a57950dfc924..0487668cd2a7c 100644
--- a/src/test/ui/const-generics/defaults/pretty-printing-ast.rs
+++ b/src/test/ui/const-generics/defaults/pretty-printing-ast.rs
@@ -4,7 +4,6 @@
 
 #![crate_type = "lib"]
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 
 trait Foo<const KIND: bool = true> {}
 
diff --git a/src/test/ui/const-generics/defaults/pretty-printing-ast.stdout b/src/test/ui/const-generics/defaults/pretty-printing-ast.stdout
index f549993c413d4..1bceb8cbb94dd 100644
--- a/src/test/ui/const-generics/defaults/pretty-printing-ast.stdout
+++ b/src/test/ui/const-generics/defaults/pretty-printing-ast.stdout
@@ -6,7 +6,6 @@
 
 #![crate_type = "lib"]
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 #[prelude_import]
 use ::std::prelude::rust_2015::*;
 #[macro_use]
diff --git a/src/test/ui/const-generics/defaults/repr-c-issue-82792.rs b/src/test/ui/const-generics/defaults/repr-c-issue-82792.rs
index c64c2974c8f8f..ca29ee9420645 100644
--- a/src/test/ui/const-generics/defaults/repr-c-issue-82792.rs
+++ b/src/test/ui/const-generics/defaults/repr-c-issue-82792.rs
@@ -3,7 +3,6 @@
 // run-pass
 
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 
 #[repr(C)]
 pub struct Loaf<T: Sized, const N: usize = 1> {
diff --git a/src/test/ui/const-generics/min_const_generics/default_function_param.rs b/src/test/ui/const-generics/min_const_generics/default_function_param.rs
index ebdb5a65bc351..b47dd2f618cd9 100644
--- a/src/test/ui/const-generics/min_const_generics/default_function_param.rs
+++ b/src/test/ui/const-generics/min_const_generics/default_function_param.rs
@@ -1,6 +1,5 @@
 #![crate_type = "lib"]
 #![feature(const_generics_defaults)]
-#![allow(incomplete_features)]
 
 fn foo<const SIZE: usize = 5usize>() {}
 //~^ ERROR defaults for const parameters are
diff --git a/src/test/ui/const-generics/min_const_generics/default_function_param.stderr b/src/test/ui/const-generics/min_const_generics/default_function_param.stderr
index 243ac0db5f55f..11df8621faa24 100644
--- a/src/test/ui/const-generics/min_const_generics/default_function_param.stderr
+++ b/src/test/ui/const-generics/min_const_generics/default_function_param.stderr
@@ -1,5 +1,5 @@
 error: defaults for const parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions
-  --> $DIR/default_function_param.rs:5:14
+  --> $DIR/default_function_param.rs:4:14
    |
 LL | fn foo<const SIZE: usize = 5usize>() {}
    |              ^^^^
diff --git a/src/test/ui/derives/derive-macro-const-default.rs b/src/test/ui/derives/derive-macro-const-default.rs
index a844f2d20237b..7c4ebca874673 100644
--- a/src/test/ui/derives/derive-macro-const-default.rs
+++ b/src/test/ui/derives/derive-macro-const-default.rs
@@ -1,5 +1,4 @@
 // check-pass
-#![allow(incomplete_features)]
 #![feature(const_generics_defaults)]
 
 #[derive(Clone, PartialEq, Debug)]